@VintageRetro ,
Before "all this" happened (the cheating, the divorce, the baby, losing your dad, and losing J), I think you felt like you had a pretty good grasp of who you thought you were, how your life would go, what you should and should not be like as a man, husband, and one-day father, how you would think and feel, when certain milestones would occur, etc. In other words, I suspect you felt pretty secure in yourself, your core, your values, and where you were going.
Having a spouse cheat, going through a divorce, having a child--with a faithful spouse or an unfaithful one, and losing people whom you love are all events that occur in life that literally shake you to the core. Sometimes people don't have a foundation in life, and when their world is rocked by ONE of these events, their world crumbles. Some people do have a foundation but when the life changing event comes along, they are so shook that their foundation cracks. And some people lose the world they had built and yet their foundation remains...and they can rebuild on it.
I suspect that you thought you had a firm foundation: spiritual faith and the unconditional support of parents and family. After your foundation was hit by
five sledgehammers, I suspect your "crisis of faith" may just be that your foundation has REALLY been hit, and now it's not quite as firm as you thought it was. Here's the thing--
you may feel infirm or have doubts but that doesn't necessarily mean that your foundation isn't there.
You've acted in ways that are outside your normal character. You've done things that lead you to question or outright challenge your image of "who you are." Well...that's not the end of the world. I am one of the most bubbly, optimistic, committed, spiritually-aware people I know and I committed adultery! Even really good people can do really, REALLY bad things because we are all fallible--but the trick is to learn from it. Go and sin no more. If you sleeping with OBS did not feel good and was not you, then guess what? You've discovered that's not you. Don't do it.

If you've been acting angry or withdrawn and that's not you, then you've discovered that your Inner Core does not value that way of behaving. If you don't value it and are having trouble stopping...go see someone who can guide you (like a counselor, therapist, pastor or priest, or mentor).
My own MIL just recently passed away, and that's just one sledgehammer to my foundation. I find myself feeling untethered and at times even depressed (which is very much "not me") so you know what? I have to be mindful and accept this new life without her presence. I have to look for the joys and let myself enjoy them. I have to do some work to get through this. And it's the same for you. This doesn't have to do with "the cheating" other than that it was one of five sledgehammers to your foundation. So I pray your journey is fruitful and that you find your Inner VR and your new foundation.