Several things in his arguments don't make sense if you follow them through to the end. So either he hasn't thought it through or he's not telling you the real facts.
Well, he came to me last night and said that he loves me and I'm amazing, but he needs to divorce me because if he stays with me, he will end up leaving the church too. He said being married to me, makes him not want to go to church and that he needs a Mormon wife to be happy and keep him on the right path (no personal accountability there). He struggles with the religious guilt—his father was a mission president and they had ten kids and all that.
Leaving the church? I was a divorced single man with kids and LDS. This is a very hard position to be in as well. The LDS don't have a good support structure for this. People with failed marriages and fragmented families don't fit in with the wards. Divorcing won't simplify that.
I might be reading too much into what you wrote but assuming that you date weekly and that you have a good relationship otherwise I'm just going to gloss over it and say in the bedroom too I assume. Divorced single men who have had a good sex life are gonna struggle going cold turkey. Will he survive that with his chastity intact?
And about the kids, it's nice to fantasize that the kids will want to flock to you but lets be honest, women tend to win that tug of war. If the kids are with you the majority of the time, what are they likely to choose? He will more than likely spiritually loose his family in divorcing you.
With him being one of 10 kids ... I would be money that he's not the only one of the 10 with "problems". I'd bet 2 or 3 of those kids are inactive or worse. Maybe I'm wrong. Who's to say.
His plan ... What's behind it supporting it? If he's trying to make a wise decision isn't it wise for him to find scriptural support for it where it's said to be a wise and prudent solution? Who is supporting his plan of divorcing you? Is it the bishop? The guidance counselor (unlikely as it's not very well thought through)? Some friend?
Which leads to a thought that has nothing to do with LDS specifically. Men don't usually leave without having a place to go. Is he involved with someone else? That's another odds statement I know. I would just recommend you be a bit more nosey.
"he needs a Mormon wife to be happy" ... Umm, are Mormon married couples really any happier than other married couples? Support that please. My experience is no and they slog through bad relationships longer and suffer quietly. Are y'all happy now? Then boom, no argument. Now maybe the happiest time in y'alls marriage was back in the honeymoon era where you were both TBM but that's no promise. To replace you with a fresh new Mormon wife ... well that is iffy too. I was there, I saw the choices, there isn't a great selection. I was a single adults rep for years. Most divorced Mormon women come with kids. Blended families is the most difficult issue for second marriages. It's rocky turf. Adult unmarried singles are adult and unmarried for a reason (or two) and will have a different set of baggage. I can't tell you that there aren't some good choices out there, I got one who is a lovely lady and a great match for me. Mormonism pushes for early marriages before people really settle into who they are to avoid premarital sex right? That means some lousy matches end up in ugly divorces which means some nice wounded people are out there.
" and keep him on the right path (no personal accountability there)" Well isn't divorce starting down the wrong path? Back to the question about who is supporting this decision ... please justify scripturally where this qualifies as "the right path". Article of faith 11 says:
11 We claim the privilege of worshiping Almighty God according to the dictates of our own conscience, and allow all men the same privilege, let them worship how, where, or what they may.
Do I fall into the bucket of "all men"? Do you really mean it when you claim this? Why then am I not allowed to worship how I may? I'm letting you do that. Does that mean I'm keeping this article of faith better than you are?
And that said, I suppose you would be willing to be his accountability partner. He can make a list of the things he ought to do to be a good little Mormon boy and you could make help verify that he does these things, like 100% home teaching, etc.
Another thing I'd share, as a single man in the Mormon church you feel a little second class. The good callings ... they go to other people. The social gatherings ... generally driven through women. He may feel second class and wish for more of those things that "normal" Mormons experience. Divorce doesn't unlock that door though. And get this, remarriaged doesn't either. Having been through forbidden territory, he will always carry a mark and many people will be threatened by him. I can almost guarantee he would never be a bishop or elders quorum president.
As a divorced man I lost 1/2 my home equity, 1/2 my retirement and am still paying a significant portion of my salary to child support. I have less influence and access to my kids then I did when I was married to my ex. Thanksgiving, Christmas, birthdays, graduation, first dates, first boyfriends, fights with their friends, cuts and burns, learning to drive, first grandchild, every success, every failure, every struggle, every fear, every tender moment where you are needed ... all these key events in the lives of your kids are colored by divorce. Some children of divorce find ways to leverage parents against each other ... and it's easier because they are already fighting. In other cases the parents take the children from the other as a punishment or the result of them getting a big head about how right they are. In other cases the children are used as a weapon to punish the other parent much to the damage of the children. I've seen all and experienced several of these. It's ugly. Divorce should be followed by a period of time to recover. How long? Depends. It's better if it's a few years to establish self again and to heal from wounds. Divorced people tend to be less happy. Remarried people don't necessarily end up happier because of some of the stresses I mentioned. Point is it's rocky turf forever and this is your moment to stake your claim
, that if he leaves you, you are going to fight for your children to be in your life as much as possible and you will hold him responsible financially and in other ways to help support them and maybe even you if alimony is due. You are not going to fold and give him all of it to just go and replace you with some Mormon wife.
So in that light, isn't it maybe worth spending a little time and money to and energy just see if there isn't some other options?
If your were looking at loosing your home to a foundation problem, wouldn't you call someone to see if they could repair it?
If your teeth were hurting and had been for months, would you call a dentist or pull them yourself?
If he resists it's most likely that he has made a choice and knows it's flawed but he doesn't want to get talked out of it and he doesn't want to have someone point out the flaws and make him feel dumb for making a emotional decision with a flawed logical foundation.
Anyway, I've gone on too long but those are some things to consider. Just take him to the end of his plan. Talk him through to where it really goes.