Right now I'm not lonely at all as I have an amazing boyfriend who I just cannot stop thinking about, and who makes me happier than I've ever been.
But a few months ago I did feel pretty lonely. I didn't have my perfect guy and my friends were annoying the crap out of me... Oh and A levels were getting a bit stressful... but all of that seems to have gone now.
Loneliness is just a state of mind, and a state of mind is always changeable. I've come to the conclusion that if you actively try and make yourself happy then eventually you'll find people that want to do the same. If you walk around looking depressed and miserable then people are unlikely to get the right impression, or the impression that you want them to develop.
So buy a new top or something, tell yourself how god damn fine you look in it, go out there wth a big smile on your face and a confident walk, and I almost guarantee you'll start to really be less lonely.