NEED ADVICE!!!! Abusive relationship

My boyfriend was in a abusive relationship, and i noticed its hard for me to adjust. I personally have never experienced something like that so i don’t know how to approach or help him. I know it still affects him. His ex still comes up a lot and it makes me really upset. I feel bad for admitting it but i don’t know how to deal with that type of trauma. Sometimes i question our relationship and whether i can deal with it.😖😖 i feel horrible