Justafriend, sounds like you're taking a lot on right now, helping and supporting your friends. But it also sounds like it's about to drag you under.
Just two thoughts to consider:
1. Friendship is a 2 way street. Your friends deserve the chance to help and support you too. Why not give them that chance? At the very least let them know that you can empathize with their struggles because you're struggling too. You may have hidden it so well or they may be so wrapped up in their own stuff that they didn't realize how much you're going through. Once they do, you may find you can lean on each other--like an A frame--and support each other rather than it being more one sided
2. There's a reason that the airlines say "put on your own oxygen mask before assisting others". You can't help anyone if you collapse yourself. So make sure you get the help you need to cope with your own issues. Therapist? Doctor? Talk to someone and see what they can do to help. And please don't feel guilty about taking care of yourself!
Sending thoughts of peace and strength your way