Uselessness while useful

So often I feel completely useless. What is interesting is that often this feeling comes while I am being useful. I was helping to train someone on a process at work and had a suddenly overwhelming feeling to shut up and hide. He was so grateful for the help and set me up to help others and my brain is now desperate for a way to get out of it. 

I don’t know why my brain goes nuts like this, but I am now wishing I could be mute the rest of the week to avoid showing people how stupid I truly am. Maybe someday my brain will stop pulling me down.