Am i a terrible person for thinking of him like this at times? PLEASE MATURE ANSWERS!?

I am a 24 year old girl living in the U.S i am originally from Colombia and and from a Colombia-Irish family. My mom & i moved back to the U.S when i was 15 but ended up going back home. I am with my partner since i was 16 and am engaged and i love him dearly. He was part of a very dangerous gang back home and i ended up leaving him as i could live with it anymore, He joined & was talked into the gang life when he was 10 years old so it was all he knew, He is now 3 years away from that lifestyle, He left so we could be together. We are both living in New Jersey near my family as my parents split and have jobs etc. I finally got myself a really good job. I still go back to Colombia to see my dad, but my partner cant come with me as he is a 'marked' man there. Sometimes at night he will wake up with nightmares from his past and what he has done, i just wish he could forget it all. He had so much hatred back there and lost control of his life to the gang. I feel terrible sometimes when i look at him and see him as an ex murderer that he was & whatever else he did but i now see how changed he is, going to church etc. I hate myself for thinking like that as i adore him. What would be the best thing for us to do? Any advice would be great & please don't judge me, Thank you.