I have allot of trust issues due to my ex boyfriend.

We dated for a year until he went away for a week and came back to say he wasn't in love with me anymore, but instead someone he met in the span of that week. We broke it off but later got back together because of me being young and him guilting me. We stayed together for another year as he continued to play me and lie to my face and cheat around with other girls and finally I decided enough was enough and I haven't seen him since.

Fast forward to today. I am in a relationship with the guy of my dreams and we are going on a year and a half now. He has never hurt me or flirted with other girls or cheated on me or anything like the other guy. He is seriously the sweetest thing. Sometimes I get really paranoid though and I worry myself into serious panic attacks about him leaving me or cheating on me and I tell him I'm afraid of this sometimes and he reassures me that he would never dream of it. I trust him with my life but my ex has scarred my mind. I don't know what to do anymore. I don't want to keep doing this and scaring myself over nothing.