My depression is ruining my friendship

About 8 months ago, my GF and I of 6 1/2 years broke up. It ended pretty bitterly due to my ex’s dismissive avoidance/stubborn outlook. Her best friend (B) works with me and wanted to stay friends. Things were great for a while, until my ex told B something that I had said privately. It was something that B had told me in confidence, so she felt betrayed knowing that I had told my ex. I had thought that it was ok since they were friends, but I see now that it was wrong. B told me that I’d grown and she didn’t think I would do it again. However, our friendship became very hot and cold after that point, which is where it remains today. We used to confide in each other how we are doing. She gave me amazing advice and support, and I tried to do my best for her. Some days are really really good and B will hang out with me for hours after she said she had to go. B gave me a really nice gift just last week. However, this past week B seemed quiet. This was right off another “bad” week. We were playing a game together and she was quiet, so I tried to ask how she was doing. She cut me off mid sentence and told me not to ask and I said something like, “I just want you to know that I care how you’re doing.” She replied, “I told you not to ask.” Shes been silently suicidal before, so I was very concerned.

Anyways, this past week B seemed quiet. I gave her space and bided my time. I saw her at the office today and things were quiet. She said she was fine, and I tried my best not to push it. I’ve been really struggling recently and I’ve been bottling it up. This hasn’t been healthy, and in fact, ended with me drafting a suicide note for the third time. I decided enough was enough and arranged for myself to be committed. I told B today that it may impact our work and that she may need to pick up some of my slack. She asked if my therapist recommended it and I said that, no, it was my decision. She dropped it after that and I asked her if it was ok for me to tell her these things. She said that it was “until I start talking about it too much.”

I’m really kind of torn. I can tell that I’m overwhelming her, but I really don’t have anyone else to turn to right now. When I talk with anyone else, it’s always “damn. That sucks.” B has been the only one to offer substantive advice.

With this hot/cold friendship, I’m really struggling to find a stable support system. I don’t want to bottle how I’m feeling, but apparently I’ve been talking about it too much anyways.

It’s worth noting that B suffers from depression too. I know everyone has their own stuff going on, so I’m trying really hard to be respectful of her and her boundaries. I think sometimes I ask how she’s doing too much, or that I care too much, and it makes her feel uncomfortable too. I just worry about pulling back too much because I don’t want her to feel like I’m abandoning her. I remember her catching me crying one day and she told me that she was sorry that I felt so alone. She said that she’d do her best to support me as a stable element in my life.

Do you guys have any advice on what I should do? I feel like I’ve done something wrong or selfish. I don’t want to prioritize my well being above hers, but I’m also extremely depressed and lonely. B has done so much for me, but I feel like I’ve taken more than I’ve been given. Every time I try to return now, B seems uncomfortable. I just don’t know what to do, other than give her space. I think she’s frustrated having to be between my ex and I. I just don’t want it to be another repeat of a friend leaving me because I’ve been sad for too long/over depended on them. People always say I’m too much.

TLDR; my friend and I used to confide in each other, but our friendship turned hot and cold. Now I overwhelm them with my depression and I’m worried I’ll be left alone