Yes, people go on disability for depression and other mental health issues. It is as real an illness as diabetes, or heart disease or cancer. Major depression is just as biological as other illnesses. It's the brain that is affected instead of the heart or other body systems. Would you consider yourself a failure if you were unable to work because of a heart illness of some sort? Or a debilitating injury? It's no different for people with mental illnesses.

Is there some way you could take some medical leave from work? Something like this would be considered a valid medical leave and if you are in the US and have worked for your employer for at least a year, then you are probably protected by the Family and Medical Leave Act. By law, your employer has to allow you to take up to 12 work weeks of medical leave without the risk of losing your job. Taking a leave now may give you some time to recover and prevent things getting any worse.

And if you find that you are no longer able to work, apply for disability benefits. I found myself in that position last summer and to be honest, going on disability was the most responsible thing I could have done. I was no longer able to work and was headed for a major hospitalization. I tried to take some medical leave, but for me it wasn't enough. If I had continued to work, I would have ended up extremely sick and would have lost everything. Now I am able to get my disability payments and help support my family.

I know how it feels like you're failing. But try to understand that this is real and it is not your fault. Anybody who says you "should" be able to do it hasn't walked in your shoes. I would seriously look into at least a short medical leave so you can have some space to just breathe and figure out what to do next. It's nothing to be ashamed of.