I think my YouTube channel with its 44k subscribers is literally the only thing I have going for me in life.
Why do you think that's the only good thing in your life?
I'm suicidal, and I like spending my time talking to people through that channel.
I understand that it can be very difficult to manage your mental health, and it's a good thing that you have something like your YouTube channel to help you feel better. Feeling suicidal is not something to be taken lightly at all though. If you really are feeling suicidal, you need to seek out help immediately or else you may do something you regret.
I know and I'm at my mental limit, but I literally have no other friends.
If there is no one that you can talk to offline, then finding a therapist is a step that you should take immediately.  You could call or text a support line and ask to talk to the same person each time, and they will help you to understand your feelings and discuss ways to cope with them.  Your Youtube subscribers will also appreciate hearing about the progress you are making.