What do you think honestly?

If you have time to read this please help me. 
So I met my ex when I was 16 (26 now) we have been on and off all these years because him moving away so far and just got hard. Longest we didn't talk was 3 years and that was because I was in another relationship but as soon as I was over with that I went straight back to my ex just because I missed him so much. Now I'm with someone that I really do love and care about but at times feel so unhappy, to make it worse I think about my ex all the time, what he's doing or if he's seeing someone else or if he's in town.. Constantly. I don't know maybe it's just cause he's been in my life so long. Do you think this is just something I should get over eventually and move on? Or worth leaving this person and making it work with my ex?