I know the feeling somewhat. I'm a cancer survivor (I had malignant tumors on my spine removed in three separate surgeries) and later on in life I went to work at a warehouse. Due to all of the heavy lifting involved with working there, it aggravated the scar tissue around my spine and caused me to suffer from Arachnoiditis, which has no cure. So being disabled as well, I have something of the same fear, but seeing as how having arachnoiditis can eventually leave me paralyzed, my fear is not being able to fully be there for my future kids.