MISSUNDERSTOOD

After reading all of your messages, i feel a lil relieved that im not alone. My family and friends say that i shouldnt be thinking these kind of things, and maybe i need to talk to someone. Im not sure if i have OCD even though i have all the symptoms for it, BUT heres my story. Im 21, and i have been with my boyfriend now for almost a year. Hes the best guy ive met. I love him, and i know he loves me. I was diagnosed with narcolepsy not too long ago.. and put on aderall. I do have to say that my medicine helps a lil with the thoughts ive been having recently, but not fully. I was interested in finding out a lil about my boyfriends past and i didnt really like what i found out... he had one true girlfriend when he was in highschool. This mind you was about ten years ago but they dated up till college. I think they were together for about three years. He didnt "date" anyone after the fact until he met me. Of course he probably slept with a few ppl but that i do not want to even know. I had a boyfriend for all four years while i was in highschool and i could give two craps about him today... ok... i found out who his ex was and what she looked like and it killed me. i saw all of her pictures and just thought WOW. i do have very low self esteem and it gets in the way of how i think. i cant help but think when he goes out to the bar... will she show up there?? or when he wants to go to a certain place... why will she be there?? or if theres a girl on tv that resembles her i think... is he thinkin of her?? ext... Weve talked about it a couple months past and he says that it was a long time ago and that he doesnt care about her... he doesnt love her and the past is the past but i cant help how i am thinking and i think its ruining my relationship. When he told me that he doesnt love her and that was a long time ago i believe him... but then once hes not around and i look at the pictures.. its almost like he never said it at all... shes not that good looking... i mean shes average but idk what it is about her... maybe that its his only ex idk but when we first got together his friends would bring her up and thats when i wanted to find out more... which i really wish i hadnt. I cannot help but look at her pictures and tell myself that she isnt that pretty and that he loves me and doesnt care about her but even after saying all those things to myself i cant help but think does he?? does he care about her?? would he sit there and talk to her at the bar while im at home sleeping bc i have to wake up in the morning... funny thing is is that he doesnt even know a thing about what im thinking. The only thing i told him is that i didnt care for everyone talking about her and he told me all of the above.. so please i seriously have to ask.. what do you do?? i really dont think that going to a therapist or talking to someone every week will help i need self help first.. does anyone out there have any idea as to what i can do to stop these horrible thoughts in my head..??