Forgiveness is not approval. You have to do it because it is how you let go of your resentment. I’m sure it’s quoted here on this site somewhere but it’s worth repeating: Keeping Resentment (and anger) is like you drinking poison and hoping the other person will die from it.

Hopefully you are active with your sons. Try to focus on that. Exercise or start cooking really healthy meals. If you already do then think about some other ways to make extra income. Even if it isn’t feasible now, in two years it may be if you lay the groundwork now. It will take some time but just focus on what you need to do to improve, not on your ex.

I’m sorry you’re going through such pain. But you are going through it. 5 months, 10, 15, however long it takes. If you were dating with the hope of marriage unfortunately that’s the price to pay. 2 years seems like a long time to realize it can’t result in that, but I do kind of understand the vacation excuse. Why play house so to speak if you know you shouldn’t go down that road at all? He said he wants someone with no expectations.

It will be difficult but try to pick 3 things to focus on and post them to remind yourself. A new hobby or an old one, a friend, charity work, regular work. For the next six months whenever you start dwelling on him again pick one of those things to focus on. Even if you’re just making a list or reading about it. You’ll still think of him but hopefully you’ll stop obsessing.

I’m sorry you are hurting on a yearly cycle. Since you are reaching out for help you are taking a positive step. And congrats on getting sober. Though the title of your post is about your marriage, the advice I have focuses on your second paragraph.
If you are stable your children will experience some stability.
If you are angry at all men your son will be affected more by that than by the amount of females he is around. He will be a man one day too. Your attitude towards men is going to be a part of him.
If you want to work, what is holding you back? Take steps to fix it. I know it will be hard but even if you think you’re unsuccessful now, after a while you will notice you accomplished more than just existing. It just takes longer than we’d like.
That is all you. The hurt over the loss of your best friend will still be there but all of the above could be worked on even if he was around. It’s your part.

The other thing to consider, not sure it’s advice, but I’ve done it myself, is to move somewhere warm. Where is he going every winter? If it’s not the weather maybe it’s the holiday circus he can’t take. Why would he keep coming back after that if he didn’t want to be with you and with his family?

“so our relationship has been very much like a marriage to me.” If you’re committed, don’t let him go.

If you’re scared of his daughter make sure he knows YOU are scared for you. You said you are setting the boundaries to protect you all but I think you should just focus on protecting yourself and let him deal with her in his own way. It sounds like the kid needs intensive therapy but if he’s insisting on having her visit he obviously doesn’t have the same fears you do. He’s afraid of losing her.

In five years if this is over there will be something else you have to work through. There always is. Maybe, hopefully, not this Big or intense, but it will be something. Love yourself more if you need to. As far as the relationship you wish you had any little step you can take to make it happen is in your power.

Move on. It doesn’t mean you couldn’t end up with her in the future. It just means don’t get hung up on one girl who isn’t ready for a relationship with you. Because she’s not ready for a relationship with you like you want nor is she willing to work for it (right now) with you.
Also, I’m not sure what all these feelings her and her new guy are confessing to each other are. Maybe they’re rather shallow feelings but they’re both having fun with it.
If she really wants to be friends with you just tell her you need a little time with that bc of how you feel about her. If she cares at all about anyone other than herself she will understand.

Yes, you deserve to forgive and love yourself.
You said you told the other person the truth, and now you’re miserable. Are you still together? You’re right in that you don’t need labels or even rings to be serious with someone. You need to be there in your own head. If you broke up, you’d probably be miserable bc of that so don’t let it add to your guilt over cheating. You admit your behavior was horrible now begin to take steps to improve. Taking steps means actively changing your behavior or response to a certain situation for the better. It does not mean just saying “I’ll never do that again.” I would say if you’re asking friends about your relationship status instead of the person you’re with (did he even know your friend was visiting?) then one active step would be learning how to communicate with a partner like you do with your friends. Another step would be to reflect on your insecurities. You admitted you were an insecure person, now 3 guilt-ridden months later, you’re not? Read through the great articles and posts on this site and really make the attempt to love yourself. It’ll take a while but you deserve it.