Replies to 'Cheated On'

I am a  31yr old seperated woman who is a mother of a toddler. I first found out my husband was cheating while I was pregnant with my son. I worked hard to get past it (I'm not sure I ever really did) and later found out shortly after we purchased our first home that he was still cheating. After 2 1/2 yrs of lies and betrayal I left him. It is a year later and we still try to make it work. I love him as he is the father of my son and someone I have known most of my life but I just dont know if I will ever trust him fully again. I want my son to have his family back but I dont ever want to feel the way I felt after all the infidelity. My husband still has not come completely clean and I think this has a lot to do with my lack of trust and forgiveness. Am I making the situation worse by trying to make this work? Should I just walk away? Am i hurting my son with all of this?