I suffer from Borderline Personality Disorder, and so as you may know, feelings of isolation and abandonment are intense. I haven't spoken to another human since Saturday. I'm sociable so this is killing me. I can't pick up any interests because I don't have the money to buy equipment to indulge in the only passions I really have.
Loneliness is no fun :(
See suggestions 1, 2, 3, 11, 12, 13, 15, 19 in the first section of this wiki page. And some of the suggestions in the sections below it, too.
I've joined chat once or twice but nobody really spoke to me when I said hello.
There are other chat rooms, too. But, in general, in online chat, when one person says "hi", it may not be enough to start a conversation. Try to leave a browser tab open to the stopdrinking chat room for a few hours, or even 24x7. You can then join in by replying to an earlier conversation which happened minutes or hours ago. Use the customary IRC ping message format. Enter a few people's nicknames, then a colon, then a message. Like this:
tealhill: VictoriaElaine: janedoe: Yep. I've also been drinking a lot more carbonated soft drinks lately, and I wonder if I should cut down.
someone ... sort of said that it's not AA's problem to deal with my mental health issues
This isn't so accurate. It is true that the meetings focus on alcoholism and not on mental health. However, anytime when a meeting is not in session (e.g.: people hanging around in the rooms or in coffee shops before and after meetings; the "hallway track" at recovery conventions; phone calls with people you met in recovery; etc.), people can talk about whatever they want, including about mental health issues.
I've joined Narcotics Anonymous to deal with my ADHD and technology overuse. I've never used any any illegal drugs, ever. Hearing the sharing at the meetings doesn't really help me that much. Really, I go to the meetings to meet new people -- not so much to hear people share. After the meetings and during the smoke break, I hang around and strike up conversations with random people. (I like to introduce myself to people and to ask them, "How did you get into recovery?") I give my phone number to everyone. Almost invariably, they always give me their phone number in return. Then I can call them sometimes.
As you open up to individuals in recovery about your mental health issues, you will notice that most of them will open up to you about their mental health issues in return.
I feel that the only way I could give meetings a go would be to have someone there for me, looking out for me, because combining my borderline and my anxiety and so on means I just can't do it alone. I think that might be a sponsor's job, but I'd need to find one, and I know I'd get attached emotionally in some way like they're a stand-in parent (I'm not the adult my age suggests) and be too high maintenance.
In his book What Addicts Know, Christopher Kennedy Lawford quotes a recovery oldtimer named Jack Hoffman. Mr. Hoffman writes: "I tell people to find up to five sponsors -- because then you realize that everyone has a worthwhile perspective, and all of those perspective maps taken together are more powerful than any one is on its own."
Perhaps you could take on a temporary sponsor, and after a while, ask them whether or not you're indeed too high maintenance or not.