Hey Doc... I am so sorry that things got to that point, and I admire your courage to come here and tell us about it. Please do not feel any shame... sometimes it just seems too dark to see any light at the end of what seems to be an endless tunnel. It's a human reaction to being under a lot of pressure for a very long time like you have. And, shame only tends to deepen depression because we judge ourselves too harshly and that makes things seem even worse.
It sounds like now in retrospect, you see this as the wake up call that it was. You have been through so much the past few years, and I know what a mental, physical, financial, and emotional burden you have had dealing with all the treatments, surgeries, and just life in general at times. You are a strong person and a person who faces adversity straight on. This one just slipped up on you... and I know you're not going to go there again.
I do hope you are talking to your doctor about what happened. A good counselor can do wonders for your mental state, or at least it did for mine. Please stay in touch and I apologize for being absent for so long from the forum. Sometimes I have to take a mental and emotional break. I know you understand that!
Take care... you've got to get back to snappin'!