(((Hug))) I know how you feel. I have been experiencing my latest (and worst) episode of depression since September, due to job stess and winter months. I know how gripping the despair can be. We've tried adjusting meds so much I don't know where I am anymore. But I am (like you are) hoping that the latest change will work.
That is something, "hope". You are stilling hopeful and that is important. You will get well, and it's absolutely amazing that through all of this deep depression, you have still been fighting to get back to work...Going through the stressful interviews etc. GOOD FOR YOU, seriously!!!! That is huge and I think you are stronger than you give yourself credit for. Keep going
Meantime, try to cope only the best way you can. I can relate to the suicidal ideation; I was there two weeks ago. What is vital there, is to take action to protect yourself. For example, when I slipped into crisis mode two weeks ago, I right away called my local crisis line and with their support we came up with a 24 hour crisis plan, taking hour by hour, planning to always be in contact with ppl, chatrooms, have someone come over or meet someone, telephone...distress line...etc..among other coping methods. I had to keep checking in with them and I ended up doing that for 3 days, but got through and felt at least stable coming out. You said you're not isolating yourself, so that is really great.
Anyway, we are here, and know you are brave for surviving.