Hello there! Your story hits home, I myself felt pretty lonely specially when I started to follow the anime route, after many years I've found people with the same interests as myself but I also learned the most important lesson in my life:
And that is Perspective.
I do not intend to say that this is the correct way someone should live, and I do not intent to offend or attack someone. I am purely speaking from my experience with the intention in mind to help someone who seems to be in a place where I was before.
I've been really fond of why do we feel lonely, why do our feelings matter so much that in some cases they even make us take irrational decisions. I've went and tried to search for that answer (and still try to find out more about, we will always keep learning) in a bunch of places, philosophy , religion, psychology, teachers that knew about this subject and regular people like friends and family. The responses are quite different as expected, but there's one point in common and that is where your point of view in life is placed. It is placed on yourself, other people, something else which totally can mess up your mood in general and make you feel uncomfortable? I'll try to share my story with you, perhaps it will make you feel a bit less lonely.
For a long while and without knowing , my perspective was placed on relationships that other people had and which I myself wished to have, trying to make myself obtain something like that and ignoring my own nature and self pace, trying to become something as "the clown of the classroom" to accomodate myself in some groups, but losing interest after a while because I didn't know how to form bonds. After many circles of doing the same thing I became numb about myself, who was I what I was trying to reach or prove why do I want friends in the first place and why do feelings matter so much.
I had the luck of my life in 11 grade when I learned about a guy named Epictitus, an ancient greek philospher which spoke of stoicism (one of the many stances , or points of view, from many on the matter of life) from there on I tried to apply everything I was learning about life from those old texts, and finally realized that I should be the center of my own life and the first and most important person in it. I felt like a dumbass when I realized I was not caring about myself, not thinking once about loving myself and trying to fullfill myself without my own power. Life is not a stale river, but most of the time it is, and if you ever feel lonely due to not having acess of meeting people or feeling lonely even tho you're with someone, you have to realize that you're not alone, you are there and you can reach happiness with only yourself.
Those things that you learn from philosophy classes (or from people and even animes) come in handy when you don't know where you are in life. About 7 weeks ago I went to college and stayed for 4 weeks in there due to exams, I didn't have any type of human interaction and felt quite lonely in the beginning but I managed to get by and feel actually pretty happy when I realized that I am here, I am the one who should love myself.
I know it's easier told than done, but as one of my favorites characters once said:
Have hope. - Gankutsuo.