I live overseas and six months ago I met a loving guy who is great however an year ago I had met a man ( who is now a friend) back at home for whom I immediately fell for, just felt he was the one and had high hopes. However in spite of him being very very attentive when I was home and although he emails very often, he never really said anything about us... anyway being so obsessed with him, I was naturally upset when he forgot my birthday... and 3 weeks later I started dating my boyfriend now, because I didn't want to wait around for him and move on with my life... I have in so many ways, except I never seem to get him completely out of my mind and I am going home soon, and will see him again...

Even though he never directly says anything directly he is kind of sweet and romantic, emailing me so often... my current boyfriend is a sweetheart but he belongs to another world... and being with him will change my life altogether.

Please advise.

By "another world" I take it you mean he is of a different ethnicity or religion? Please be VERY careful committing yourself to such a relationship. Too many cases end in disaster as your two lifes have been so very different and culture clash is inevitable.
I wonder if his "exoticness" is what attracts you? Whereas dear, sweet Mr Reliable is too familiar to you.
You need to think seriously about how you want to live in the next part of your life and judge dispassionately which one will respect you and look after you in the way you are used to.
Perhaps a chat with a counsellor might help.