OP,
I think @tarasmalatarocks is giving great advice.
The thing is you are putting yourself under huge pressure to forgive, forget, move on.
You can't force forgiveness.
All that does is cause additional distress and anxiety.
I think you have to accept that you are going to feel like this for as long as you feel like it.
You want to feel better so that you can make a decision to stay.
Again, this is you putting massive pressure on yourself.
All of the things you are putting yourself under pressure to do, benefits him.
You need to be thinking of you.
I think you need to try and accept that things are unlikely to ever return to how they were.
I think you need to accept that you may decide in the future that you no longer want to be with him.
You best chance of getting through this, is stop putting pressure on yourself to forgive and forget.
Give yourself time.
Make no promises.
I don't believe it is possible to feel the same as before, but maybe you can move forward with him and feel something different that is still positive.
I agree with the therapist mentioned above, put yourself first from now on.