why is this so hard on me?!?!?!

It's normal that you should be confused on how you feel. You put your trust and faith in your husband and he has betrayed that trust. I can only tell you from my experience that he may not be able to change. Mine was also into porn in the early years and that has escalated to something I can't bear to talk about. I hate to think of the number of times he has cheated on our relationship. My ex also put himself first in a passive agressive way. He hid his affairs well. He was high enough in his company to doctor his paycheck when he took off work to meet with one of his girlfriends. I wish I had know all of his vices a lot earlier. I would not have been married to him for 33 years.
Perhaps the heaviness in your heart is sadness over the failure of your marriage and the divorce that may be happening.
Yes, he does need counseling. You say you are not sexually attracted to him. Do you want to live many years with someone you are not sexually attracted to? You need to see a therapist on your own and try to work thru all the feelings that are overwhelming you right now.
Only you know if you can work thru these problems and stay in your mariage. No one can tell you what to do. That decision is yours. We are here to listen. I wish you luck whatever your decision. 

He needs counceling.