Some of it may be from his transition. He has a lot on his mind, and therapy can sometimes seem like a set of hoops to jump through, rather than something beneficial. It can be hard to focus on a the jists of a relationship. But some of it may have to do with things going on in the relationship.
It is hard to help with what little information I have. You have every reason to feel insecure, it happens to a lot of people and it’s hard for others to see how this affects people. If you are acknowledging that you feel this way make sure you tell him. Ask him what you can do to be less clingy, and tell him what makes you feel so insecure. Make sure you guys try to talk. Reassure one another.
Another thing may be if he has started T recently or not. This can cause huge changes in mood and behavior. This is something you really have to ride out and gauge how things are going to happen. After the adjustment period things may return back to normal, but sometimes they don’t, it really just depends on the individual.
In your case you could try giving him some space. Tell yourself that it is time to try to trust him again. Relationships that continue without trust tend to be problematic and do not end well. Give him time and trust and respect. If he cheats again then he does not respect you and it is probably time to leave, for yourself. You always deserve loyalty and respect. It’s going to be stressful and worrisome, but this happens sometimes and it’s not your fault and has nothing to do with his transition.
So, just try to keep that communication open. Validate each others’ feelings, and reassure one another. Be respectful of what the other is feeling and discuss ways to resolve the situation.
I am sorry it took so long to reply. I have some messages saved in my inbox and yours was bumped to the bottom? Anyway I hope everyone is well!