I know how that feels, as do most on this forum. There are so many things swirling around our heads and we can't just let it out like others can, such is our curse. Well at least we got each other to talk to. Trust is a whole different issue but hey, anonymity sometimes provides a substitute to trust, to a certain extent. Even then though, conditions don't just disappear.
Tis true. I envy people my age, they have it all going for them. Friends, academic smartness, just a great life in general.
If you feel bad about being lonely, you should do one of two things:
1. Accept that you are lonely and decide that you don't need anyone right now. This is not the same as not wanting friends or actively avoiding people. Having friends is a good thing, but not a requirement for being happy.
2. Decide that you are going to do something about your situation. Make some friends! It is not always easy, but the more people you talk to and the more people you try to make friends with, the more friends you will make.
This choice can be applied to almost everything that makes you feel bad: Accept it or do something about it. If you don't accept your situation but don't do anything to make it better, it is natural that you will get mad and frustrated! This can be hard to do, but I've found that it really helps.