What Causes Weakness Of Legs And Arms?

I have had muscle weakness since 1995. Three months after a bad car accident(no physical injuries), I noticed weakness in my right hand(fingers). Within about a month or so it move to left hand, then left leg and then right leg. Have had numerous tests for muscle disorders, all of which were negative. Had lymes disease appox. 1 or 2 years previous to onset. Have been taking levothyroxin(currently 125 mcg)since 1991.Last year I was perscribed an antidepressant/anxiety pill, Cetalapram. That pill caused me to only sleep 3-4 hrs, excessive spending, more energy. Dr. thought I was bi-polar. It also made me able to use my arms and legs again. HAd to stop taking pill because of side effects mentioned. Also when I started the cetalapram I was dianosed w/ diabetes. In Jan. I found out I have type 1 diabetes. No history of diabetes in family. Since I stopped taking that pill my legs and arms are weak again, I try working out but that does not help.