It sounds like this has been very isolating for you. It is a lonely place to be.
I relate to this:
I’ve always been very strong minded and was never impacted emotionally in any significant way prior to dealing with infidelity although in hindsight i realise that probably wasn’t healthy
I probably over-suggest this book, but it really illuminated to me why I was this way. "Rising strong" by Brene Brown.
It sounds like you may have avoidant tendencies, and then it piles up in the background. This of course in addition to just being hit with a major trauma, there are aspects of this avoidance that may be coming to a head for you.
It makes sense to me that you don’t want to talk to him about it. He is the one who did it, and regardless of what your logical mind thinks, your reaction is to keep him at an arms length. You can’t trust him so how would you expect to feel emotional intimacy with him?
Also I am going to guess because you are a fellow feelings stuffer, you feel disconnected from not just him but yourself. And because of that everything feels jumbled and you wouldn’t really know what to say to him. But you were able to express it here. For me sometimes writing it down is easier for me to sort.
Finding the energy to heal in the midst of that is nearly impossible. And it’s sort of feels like from this post that you feel guilty that you can’t be a certain way for him.
My recommendations would be to start doing some of the following. Not all at once but build up to these things.
1. Decenter him for a while. Give yourself permission not to show up and be what he needs. This will take practice to lean into. But until you can start to listen to what you need and let those obligations fall, there is no way you can ask what you need in the relationship. Or have clarity over leaving the relationship. Your mental health is the most important factor here, nothing else works until you you can stop putting all these pressures and expectations on yourself.
2. Carve out some time to do what you need. Whether it’s to take a bath or go try a new hobby. Consider joining a group based hobby. This sounds stupid but it’s mental rest to focus on something else that you can lose yourself in. I am not saying avoid, this is energizing because your mind starts to slowly replace how you use creativity. Often creativity gets drained by the going over and over things. It’s normal for your brain to want to do that, but you have to slowly adapt towards being able to enjoy something again. It also gives you new people to connect with as well as something to look forward to
3. And while it doesn’t feel like it’s possible some days, try and get out and get exercise/spend time in nature. This can help boost your brain chemistry and energize you a bit. There are likely hiking and walking clubs in your area or maybe just join a Zumba group even. Exercise has a big impact on brain chemistry.
4 Practice asking for exactly what you want. You deserve to receive.
5. Tell your therapist you don’t feel like you are making progress. Perhaps they will remind you of things you haven’t considered, or perhaps it’s time to try someone new.
6, Spend some time feeling your feelings. Start small and in short bursts of time. When we numb the bad we numb the good. Also, until you acknowledge those feelings they can’t have movement.
7. Treat yourself whenever possible. Try giving yourself options and pick the ones that sound most exciting to you, even if right now it’s only slight. Be good to yourself, look at your self talk and try and assess whether you would talk to someone you love this way. Fill your own cup as often as you can even with small things. Cut some flowers and put them in an area you spend time. If you can afford to take a trip by yourself or with a friend.
These things won’t fix your marriage but they will help you feel better and reconnect with yourself. As you do this, you will start to feel stronger and your energy will return. Don’t even worry about making a decision about the relationship, that can wait until you are stronger.
Best to you. Be good to you. Make yourself the biggest priority. Everything will fall into place from that. I promise. The more you do this the more you will find that you start looking after what’s best for you. That will bring a load of clarity. But it won’t happen on its own.