I think I still love my ex!!!!?

I think i'm still in love with my ex, we split up about 10 months ago, very valid reasons, i was nosy shouldn't have done it but probably saved me bigger heartache, he wrote some nasty stuff about me to his friends male and female ;-/, had no signals that he stopped loving me, he proposed and couple months after that read the messages!! i've not seen him since he moved back to poland but seem to be obsessed i know he's got a girl now and most probably in love with her, we lost contact shortly after he met her!! even though he hurt me i still think about him as he was my first boyfriend in terms of etc, i've been single all that time, had a bit of a fling but can't manage tomeet anyone decent that i could be with, i am insecure and my social life is with people that are either with someone or got no single friends, most of all nobosy is showig any interest in me!! How can I forget or try to erase him from my memory??