I have been having the most difficult time concentrating, have nausea periodically, have really weird urination patterns (sometimes when I drink lots of fluids it all stays in my body and other times it all comes out), often have headaches, dealing with depression, get flushed for no reason, my heart starts beating hard and fast for no reason at least once a day...what could this possibly be? I have also started to lose what seems to be a lot of weight...