Welcome to the Forum, I hope talking here will be a help. You have broken the ice by writing a post and setting out a big problem, being alone.
I guess this can have two parts, firstly the obvious one, a lack of people to be with and I guess there are things one can do to meet others, things like socializing, volunteering, study, joining interest groups and so on.
However that may be only half the story. The cliche is "one can feel alone in a crowd". You mentioned you have always felt alone and distant from friends and I'm wondering if that isolation is caused by just how they are or if you have some sort of barrier stopping you from getting closer.
I'm no doctor and would not be able to draw any conclusions except to say in my own case (I've PTSD, anxiety and depression) I've experienced long periods of feeling apart from people, and have also had quite uncharitable views of those I've known, not necessarily justified. This has been as a result of my illness, and lessened as I improved.
I also had that feeling of hopelessness and felt, because of the way I was, things would not change. I was very wrong, they did change, for the better.
So if you do not mind me asking, have you been to the doctor to see if you have something similar? If you have not I'd suggest it might be a good time to do so (in a long appointment)
True friends are hard to find, in a long life I've found two or three, whereas acquaintances are common. Do you have any family?
It would be good if you felt like returning here and maybe saying a bit more about yourself and your life