You can find friends anywhere (I found couple at my local gym and philosophy club) but please allow me to say that finding friends doesn’t seem to be your problem. My concern is that you are putting too much pressure on the situation. Have you considered altering your opinion on friendship and/or revising your requirements?
There seems to be too many limitations and expectations on your end.
It is not always easy to have one solid friend. Everyone is a treasure and has something different to offer. Why do you want to find one solid person? Yes, It does sound safe and warm but also too much to put on one person.
I am sorry that I am asking these questions but I cannot understand your perspective. I usually beg to find good and kind hearted people (which has been very hard to find). I got no other requirement in a friend.
I am a loner as well and unfortunately I have isolated myself way too much. I understand the feeling.