Hi-
A couple of things jumped out at me:
When couples get together very young sometimes there aren’t the skills needed for a long term relationship. Adding to that, our frontal lobes are not formed. So my first piece of advice is to maybe invest in learning. Dr. Gottman has some great books and tools.
I also when I was younger wouod point at we never fight. But conflict and conflict resolution are two major skills to have. When people don’t fight, it can mean that they also don’t speak up. I am a very accepting person but what brought me here really was that I was avoidant and didn’t recognize my needs and wants and convey those to him. I was always thinking "let’s just have a good day today" and I would brush things under the rug.
My husband and I have similar sensibilities, and we don’t really "fight" either. But we have both gotten more self aware and less avoidant. I found that I actually had a lot of unstated expectations and over years of marriage, kids, bills, and life in general those can get lost and rebound as resentment.
I also think because you guys got together very young some couples like that can be codependent. I am not saying you are but that would be part of the education that you could get or seek through reading or through therapy.
Not being able to just drink one drink makes me think that alcohol may not be the best thing for you, even with your man present.
Next, you are carrying a lot of shame, guilt, etc. and we all do to a certain extent. But life is long and carrying excessive amounts will affect every aspect of your life. Ask me how I know!!! I like the book "rising strong" by brene brown because it allowed me to see how that was disrupting my ability to experience connection. Most relationships are attachments, which is a normal aspect, but connection is about being vulnerable, and feeling emotionally safe, and all sorts of things go into that recipe.
Lastly, my feelings are honesty is important for excising rot. Building a foundation on honesty is usually best. That being said, I don’t know what details you are holding or their significance. I think it’s important that our significant others know everything pertinent. We all can recall details or additional stuff that isn’t significant, nor does it change the picture. But if you said "we didn’t do xyz sexually" because you know you didn’t do that with him- that’s a problem. Both from a truth perspective, but also from understanding yourself.
I think IC is always a good idea if you can afford it and genuinely want to become
More self aware, work to resolve past trauma, and learn to have a different relationship with yourself.
Our relationship with ourselves flow into all our other relationships. If we don’t love ourselves no one will convince us we are worthy of love, and over a long period of time it’s easy to start blaming the relationship or the spouse for not feeling loved. But it’s our responsibility to know we are lovable and that our needs are communicated.
I also would look past the alcohol and ask yourself more curious questions about other contributing factors.
You are very young and life is very long. You are redeemable and you need to see that in order to overcome the factors that likely feed into the heavy drinking and cheating. It’s not a life sentence of you deal with those things now.