Lithium Carbonate and muscle weakness

My joints all over my body are painful. I don not know if it is a side effect of lithium because I take other medications. The drugs include femara, niravam, cymbalta, famvir, calcium 1000 mg., a multivitamin capsule, glucousimine, echinacea. please give me some advise as to why I get veryt painful joints and the back of my neck pops constantly throughout the day.

I was given Lithium for my bipolar disorder, I was not on it long, maybe about a week before them side effects hit me, it made me sooo weak that I could not even lift my head up, I will be eating and take about 3 chews and would be extremely exhausted, I found out that extreme muscle weakness was one of the severe side effects so I stop taking it and now I am on Prozac