Hi Nobody's child
It sounds like you are a very active person so feeling so alone and isolated must be very hard.Have you tried to talk to a close friend about how you feel? And as the others have said talk to a T if you have have to and see where you could make some changes in the way you look at yourself.
All you might need is just a word or 2 of encouragement and then you might be surprised at how good you feel after off loading some of your burdens if you want.
Unfortunately in society today everyone is so caught up in their own little worlds that they sometimes forget the people around them, so maybe just by letting someone else know how you feel may break some of those loneliness bonds. I hope that helped
And there is always this forum where you can interact with others that feel the same way,and get some tips on how to handle these feelings you have