I left him

I have a 3 year old son from another man(didn’t work out) and now I am currently 3 months pregnant with another mans baby who I love more than anything in the world. He was amazing to me and treated my son like he was his. He was always nice and polite and my family loved him. I found out he had been cheating ever since we got together. I am 22. He is 21. One woman he slept with was a few days ago and she is in her 40’s with 5 children and grandchildren. We have known I am pregnant since April. I don’t know what I did to deserve this. I’ve always put others before myself and been the kindest human to anyone and everyone. He’s slept with other women as well, including his ex. He was speaking with other multiple women. I don’t understand and I have never been as hurt as I am before. I feel very empty. He never ever seemed like the type of man to be that way. He was so kind.... I’m devastated. He’s begging to see my son and I refuse. He’s begging me to give him a chance and tells me continuously that he will change. I don’t believe any of it. I feel that he will continue cheating if I were to give him a chance. Kind words please ... I need support.