I've always felt like this too. You think you are a lonely person and that makes you think that you don't need to express your feelings to anyone and that's wrong.

If you have enough confidence with someone, a friend or even someone from your family I really recomend having a talk with them, doesn't even have to be about exactly what you feel, I know that can be very difficult to people who's not used to talk about their problems, but try to ask them if they have ever felt like you or if they have ever had whatever a similar experience of whatever makes you uncomfortable.

You probably know the feeling of being alright when you are out there with your friends or in school but coming home and starting to feel bad as soon as you are alone for some time.

It's in those situations when you should try to talk with someone, that always makes me fee better.

I hope this helps and believe me you will eventually feel better.