I know from experience this is hard but u just gotta cut your losses... whether they mean it or not, if they make u feel like an "add on" then somethings not right. I found myself in a very similar situation at about ur age... although i prob had fewer "friends" :cheesy: it was really damagin my self esteem and compoundin upon the prob as i didnt think anyone else would get me either.
Dont know what your into but i psyched myself up and found my local RPG club. Findin like minded people really helped and after 15 years a couple of those people i still consider friends. But thats how it goes... ive prob got 1 friend left from primary school.... 3 from high school... 2 from tafe and a few from work.
I like to think ive trimmed the fat and kept the best bits
lol