How can I end things...

long story short. I was with my ex for 2 years and after he lied to me about going out and drinking and ending up getting a DWI and facing deportation I ending things and jumped into a new relationship. My ex ended up getting out and I thought about getting back with him but after everything I did for him the first day he out he gets drunk bc I didn't want to see him. I decided to stay with the guy I'm with bc I felt I deserved better..we have been together for about 6 months. but I am still not over my ex of 2 years. I know he did something stupid. but we all make mistakes. he begged and begged for me. I ended up braking up with the bf for my ex cause I just couldn't get over him and still wanted to be with him but it hurt me leaving my bf. so bad. he did nothing wrong. I ended up getting back with him and told me ex to just stop trying with me. he was hurt...but recently again I've been missing him so much and tbh only really see a future with him. I really care and have strong feelings for the guy I'm with rn but I feel like I'm doing him so wrong thinking about my ex and wanting to get back with him. my bf rn will hate me so much for this being the second time i did this to him especially since he had to be the one telling my ex I wanted him instead and to leave us alone.. ...I don't know what to do. 2 years with my ex I can't just get over. and I know things will get better between us. like trust and everything.. I want him so bad and I know t. I just don't want to hurt anyone...I'm stupid for even getting involved with a guy right away thinking it would be easy. I didn't put as much needed details just to keep it short...but what should I do...