Yeah, one of the crap things about being drug through the nonsense that is infidelity is that through the roller coaster, the emotions that come out are not necessarily the ones that you most like to see on yourself.
Here's the thing - it gets better. It is slow and a lot of work, but, truly, you can heal. You have endured a lot and the life experience will give you a different perspective, but the authentic core of your personality can return.
Are you in counseling? That can help. Also, finding a productive way the get rid of the anger and hostility can help. Running and journaling helped me, but each person has their own unique niche. There was an SI member who kept a trash dumpster and baseball bat in her garage. Whatever works.
A word of caution - the healing is not linear. There will be set backs, but slowly the set backs will grow further apart. This hell is temporary. There is a a good life out there, and you can certainly be the person you want to be.