Yes, he's being unfaithful but come on, you cut him off sexually for 2 years. How long is a man supposed to be sexually cut off before he goes out and finds another for sex and affection?
You say want to salvage your marriage yet you don't want to make the first move. I'd bet my next paycheck that you could snatch his heart in a second. No cheap woman that's willing to sneak around with a MM can compete with what you offer. ONLY with you does he have honor. Only with you can future grand kids come to see grand pa & grand ma TOGETHER.
Wives don't sleep in the spare bedroom just for fun. When a spouse has a history of addiction, are controlling, angry, passive-aggressive, emotionally abusive or are seeking others to stroke that enormous ego we lose the love for our spouse bit by bit. When we speak about how these acts have hurt us and how we want these acts to stop and we are either not heard or lied to, again, we continually step away from this person we now wonder if we ever knew. Sure we struggle, we struggle with all kinds of fears....how will my kids do if I leave, what happens to me and my future, how do I make it, what will my friends and family think, and if we are religious we wonder how we can be forgiven or if it is possible, we wonder if we should just stay and make the best of the life as it is. It takes TWO people....COMMITTED to one another and willing to honestly and earnestly work thru the tough times together. That means that OP's husband should be going to AA meetings but does he want to stop or does he even see it as a problem.
I ran into this same scenario in my own marriage. My ex is an alcoholic who sees nothing wrong with the way he drinks and when I say alcoholic he drinks every day, at least a bottle of wine...sometimes 3-4 other drinks on top of that.....I am surprised his liver isn't pickled yet. He told me he would not stop drinking and he had no problem. That was just a tiny spec of the problem and I suspect the same with OP. My ex would do all kinds of stupid stuff when he was drinking....it got to a point that I would leave the room or even leave the house to get away from his sickening drunken stupors. Like OP, whose OP is/was military, mine was as well and that takes on a whole other hardship with moves and raising kids without the help of your spouse, following his career even when you don't want to and making the best of every situation you are in and every place you are sent.
So did the OP's husband reach other to other women because he didn't like what was going on at home and decided rather than addressing it he would see what thrilled him, did the responsibility towards his wife and family force him to start seeking other women, or is this just something men do and find it harmless to their marriage because he had no intent to leave his wife even though he she spending no time repairing damages or working on making a relationship with his wife?
So you want to ask if it was possible OP's husband started seeking other women because they weren't having sex. Let me tell you, women are very well aware what makes men happy and wives will do their best to keep their husbands and families happy, to a point of neglecting their own needs many times. When so much hurt and damage has happened without proper resolve a spouse will eventually back away to save themselves any more hurt. OP was hurt, she had needs too but she wasn't seeking other men to satisfy those needs. She did, and probably does, still love her husband and is very torn about the decisions she is making right now.
No relationship works if it is one-sided.