I want to skip over all the things hopefully you already know. Like the "hole" is transitory and that there is a future for us, we only have a harder time forging it.
I just want to mention that if the effects of the depression persist in affecting your work performance (as it did mine), before you assume all is lost, consider that there are disability benefits for depression. OK so they aren't anything to shout about, but anything helps. I haven't worked now for 10 years. It has been very hard and at 54 I have no illusions about how hard it would be if wanted to reenter the work force. But the point is that I continue to do everything I can to stay out of the abyss.
So if you want to keep working and stuff, then do everything you can. See a therapist. Take psych meds. Get and keep healthy. Believe me you really should try to keep working. But if it doesn't work, do not let despair get you. There are ways to keep surviving.
It does pass believe me i have been suicidal all week and well it has eased abit so there is hope. Do you take medication? Try distraction that helps and talking to whoever can help you, just do what you can, and take each day as it comes. Take care
If I were you I would go back to your doctor or seek a second opinion.
Work sounds like it is putting a lot more pressure on you than you can reasonably cope with and that sounds as though it could be impacting your mood.
Talking to your doctor and a psychotherapist and accessing appropriate care may help.
Are you able to get a medical certificate for work, etc? I don't think you can realistically be expected to recover with all the work-related stress.