My ex is ruining my new relationship...

About 6 months ago, I got out of a terrible relationship. He used to cheat on me, use me , mentally abuse me and occasionally physically, and manipulated me into thinking it was all my fault. He cheated on me about 10 times and made me feel worthless, he cheated on me while I was pregnant and I unfortunately had a miscarriage most likely due to stress of him cheating with his ex constantly.

Anyways, I got out of this horrible relationship and for about 2 months now I met an amazing guy. We’ve had nothing but a great relationship with normal small ups and downs, but my trust issues and anxiety and insecurities are gonna tear us apart. My ex ruined my self esteem and my ability to trust people, but my boyfriend doesn’t deserve it at all because he’s nothing but great to me. Recently we got into an argument because a girl sent him a snapchat and I freaked out and accused him of talking to her, so he proved to me he wasn’t by messaging her asking when’s the last time they talked. Oh god I felt so extremely embarrassed and bad after. He didn’t deserve to be accused of that when he’s never given me reason to not trust him... Luckily, he is very understanding of my issues because of the horrible things I been through.. He works with me and doesn’t get angry, or upset. He just tries to comfort me and work my confidence back up and gives me any reassurance I need...

Have any of you had this problem? It was 6 months ago I do not know why I still have these issues.. My boyfriend mentioned me going to counseling for it.