MY BF/HUSBAND CHEATED ON MY 1ST COUSIN

We are married for 7 years and been together 13 years. Just 2 months ago I found out that my husband is a father of my cousin's child.
She got pregnant 3 months before we got married. They were hooking up for 3yrs before we tied a knot. I was working abroad and they became closed and not knowingly it turned to a relationship. I am not sure if it was serious but all I know is they cheated and they caused so much pain. The problem is they had communication since then and just stopped 2 months ago since i found out. I read all the msgs though it seems that there was no relationship but my husband was always saying that he missed her so much that he will always be with them forever. I do not have child on our own yet. The day I found out that I was pregnant was the day i read all the msgs. Unfortunately after 2 weeks i got miscarriage I was so stressed that I couldnt control myself not to get angry. ( i know it was my mistake why i lost the baby) i let my emotion to overpowered me and i feel sorry for everything. By the way, my husband msgd my cousin that he is already contented with their child so he doesnt care anymore if i cant give him a child.
I planned to leave but just cant because for now I have nowhere to go.
We were ok , it is on and off. There were days I am ok and most of the time i am really out of control. I dont talk to him, i cant look straight to his eyes.
By the way, I never shouted on him after i found out. it is just me if i am hurt and in pain and upset i just keep quiet and cry. So it is been already 1 week that i am not talking to him. I really dont know what to. I am so hurt with the msgs i read , i feel his sincerity in every words and i feel like useless and they took away the pride I have. Now my mind is unstable as i really do not know what to do. I still love him but I cant stop in getting so mad towards him and to my cousin and even to their child.
I confronted my cousin and denied that my husband is the father of her child but it is too late i read everything. Please help..... I have no one to talk too. I am alone fighting this pain.