breakup pain :(

my boyfriend broke up with me three weeks ago. i have mild-severe anxiety and i can’t seem to quit checking his snap location and checking to see if he is on IG and i wonder all the time what he is doing, and frequently convince myself that he is already seeing someone else, which he definitely could be. i’m trying to get over it but this is making it so much worse and i don’t know what to do. please help if you have any suggestions