Googley I can totally relate to what you've been going through... I have tried over and over to reach out and make friends with people but they never care apart from when they 'Need' things from me like exam notes or advise or some other favour to boot...I am a very lonely person as a result but there are a handful of people that have seemed genuinely friendly towards me and as a result of that i havent given up on them cos even though they dont really keep in touch they were kind enough to embrace me when the going was rough...
I suggest you keep in touch with only the genuinely friendly people and shut the door on those who only come to your doorstep for advise on what clothes to wear for their engagement and then disappear for another four years before popping up again with two kids in a supermarket...
Lots of hugs!