I am exactly the same and have been for a long time. Its hard. Loneliness is a nasty thing and its a killer. I think a lot of the time 'normal' people just get scared of depression and things like that. They don't know what to do or say and just avoid. Others try to handle it but can't and eventually back off and leave you behind. Of course a minority are selfish unfeeling individuals who will ridicule your feelings and difficulties . But its all just human nature.
However friends can be found/made but you have to actively seek ,find and cultivate them. Its hard and difficult because it sounds impossible ,overwhelming ,scary and way out of your comfort zone. I still don't have the courage to do it myself.
I suppose I am trying to say you are not alone. I and others here understand. Also , don't think less of yourself because of your fears and difficulties. You are worthy and deserving of friendships. Truly.