slept with my ex multiple times. think it was a mistake

"Don't you think that if I was madly in love with you I would have proposed whilst we were together?

What if I meet another girl that I connect with and decide I want to be with her

What if I sleep with someone else 

I realised that what we did on New Years was a bad idea because I just really wanted sex

I was talking about our situation with a girl at work and she said it sounded like I was using you

What if, in a few months time I sleep with someone else but then run back to you

I feel like I'm the only one that can hurt you, because what can you do to hurt me

I just want you to sleep with someone else and I'm not sure if it's so I would feel less guilty about sleeping with someone else

Even when we are together I think about fucking other people

I need to fuck someone else, not even just for the sex but it's a male instinct"

I'm at a complete loss of words, I feel betrayed and really hurt, I moved for him, which required me to quit my job and add 2 more years onto my degree. 

It's been playing on my mind and I just don't know how I'm supposed to feel. I'm still in love with him. 

Anyone have any suggestions on how I can stop loving him, because I'm over feeling hurt. I tried going on a date with a guy but I just am not interested in anyone else, and don't seem to find anybody attractive. I honestly feel like I'll never be able to feel like this about someone else and it really sucks. 

P.s I was his first gf and everything, we are 20 turning 21 this year, and I know that's young but still. I feel like absolute crap and every day without him just hurts more 😔