Loneliness can and does hurt. I don't have all the many friends but I do have a few that i can call on at anytime of the day or night - this helps.

"He's already muttered quite a few things that make me feel better than her".... Am going to be harsh (sorry in advance!). What's the bet that he muttered lots of things about you to her also?

You are so young to be going through these struggles. I feel for you. I am an overly emotional person (as we all know haha). I put myself back in situations are are bad for me.. similar types of guys over and over.. Now I have stopped considering the what if's (for the time being) and just taking it day by day its easier.
I think you should have nothing more to do with him, it will help you grow as a person and find what you want in life - I'm 30 and I still am figuring myself out, therefore you have a lot of years to grow and reach your full potential! xx