drug addict ex

Katie
When I was 16 I dated this kid a few years older than me, he was my first boyfriend and after a while he took my virginity. He was mentally and physically abusive to me but I felt like I had to stick by his side because he started becoming addicted to pills. He stole from me and looking back 5 years later I feel like it's partly my fault for "supporting" him, because he eventually became a heroin user and one night I found him shooting up. I've never really shared this with anyone and felt like everyone on here is so supportive and helpful. 
Anyone been in a situation like this??