Worried parent

Hi, I was hoping someone could give me some advice regarding my 18 year old son. He has had such a lonely time of it growing up, he suffered bullying in his early school life which resulted in him having to move schools on more than one occasion, when he eventually found a school he felt safe in he managed to make a few friends, or so he thought, until one by one they turned on him which resulted in online harassment, this has left him with no self confidence and severe trust issues, all he really wants is friendships. He spends all his time either online gaminor doing artwork in his room, I'm so worried about his mental health as he has suffered a few breakdowns in his young life, I wish I had a magic wand that I could make everything good for him. please if anyone could give me some info on any form of social outreach for him where he could devolop friendships, it would be much appreciated