Does anybody know what i should do about my almist relationship????

so yeah me and this 1 guy were almost in a relationship for like a year...we were basically just waiting to be together but after that almost year he got back with his ex and our almost relationship was ruined...that was like last august, since then i cant seem to get him out of my head, i dont really have a desire of being with him but i still feel like we are unfinished and there is so much more we have to go through and work out....wnat should i do...should i stick it out or let him go?