Need some Sense Knocked into me!!

Well.. Basically I had a fling with a guy for 2 years which became a relationship when I wanted to end the fling.. After one year, I felt that the relationship had no difference from the fling.. I decided I shouldn't stay.. It had been 7 months since the breakup.. We haven't really talk for about 3 months coz the breakup was so painful that I decided to leave the country permanently.. I can't stop thinking of him.. I can't stop having these wishful thinking that things might start again when I head back someday.. 
Can someone pls knock some sense into me??!! I'm feeling so miserable.. Especially now with the winter.. Coming from a tropical country is not helping.. :'(