Do not give up yet! There are still so many weapons in the arsenal, I promise!
So, you've tried the usual medications and they don't seem to work for you. That's valid. I agree that in some cases they just take the edge off. Let's move on to other ideas:
1) Have you been thoroughly checked out medically? Again, tumors, thyroid conditions, and hormonal imbalances can greatly affect mood and I would want to be doubly sure that we aren't fighting a beast that's more physical than psychological in nature. For example, I had a patient once who had chronic hypothyroidism that didn't present with the obvious symptoms. The depression was overwhelming and they just kept throwing antidepressants at it when what he needed was synthroid.
2) Have you been evaluated for Bipolar Disorder? In another case I had a patient who was actually Bipolar, but hadn't had a manic episode in years. The SSRIs didn't work at all, but Lithium did. If Bipolar is misdiagnosed as just straight depression, the right meds might not be on board.
3) Has your doctor ever tried adding a stimulant medication to your regimen (like Ritalin)? In severe cases of depression, this adds back the energy that you've lost, along with the will and stamina to keep going. A vitamin B regimen helps with this too.
4) A Cytochrome P450 test. This is genetic testing of the enzymes that process drugs in your liver. If your Cytochrome P450 isn't working the way its supposed to, you can't metabolize the medicine. If you can't metabolize it, you can't benefit from it. If your local hospital doesn't do the tests, there are national laboratories that do.
I want to keep that little pseudopod at bay.
Perhaps a little history - why do you think your children have "turned away"? What is your relationship like now and how would you like to make it better?
PS - there is no disease in the world (including depression) that can take away what you have done for them or what they will continue to do in this world. You have much to be proud of and thankful for - its just that recognizing this through the fog of depression can be so very hard. I'm trying to help you remember.