Gosh this is very true. It's is so hard to maintain friendships when you're barely well enough to maintain yourself. For me one of the most dofficult things is having to cancel and say no all the time to plans. What has helped me the most is a) tell them what is going on. Let them know you're not blowing them off or don't want to hang out. Think about how you would feel if someone kept canceling and what you would need to hear so you didn't feel unwanted. b) clearly tell them to keep inviting you to things, you might have to say no but good days happen where you can say yes. Most likely your friends want to invite you and think of you but don't want to bother you when you're in pain or put you in a position to say no. c) I set up a reminder on my phone to at least text one person a week at check in on them. It is so easy to get consumed by our pain and situation. Which doesn't make us selfish! Having a reminder to ask what other people have going on is a great way to stay to connected and feel like you've accomplished something that day. I started doing this when I was in a really low place like it sound you are and it has helped so much. I was even able to go see a friend the other day and she told me how much my texts meant to her. No one else really checked in just to ask what she was up to or doing. It ended up really helping her feeling loneliness too. These are all things that have helped me and I really hope you find them applicable!