crash&burn,
It is normal to not be able to support others at times. And you aren't burdening those of us who are in a place to support you. Some days I can, some days I can't. That's what PC is all about.
Based upon what you wrote, my suggestion would be to explore taking anti-depressants. They won't cure you; they won't work immediately, but if you find the right one, I've found them to really be helpful. I've been on anti-depressants for many years - still have up and down times, but know taking them keeps me more stable, focused and able to interact in life.