When I was taking it, it only worked first couple of days then I had to increase the dose to feel anything. Then I had a very strange effect of being tired but

When I was taking it, it only worked first couple of days then I had to increase the dose to feel anything. Then I had a very strange effect of being tired but unable to sleep at all, as if I was sleeping awake if that makes sense. After taking 600mg to see if this fights fatigue I was not able to sleep for a couple of days. I still have not found how to tackle the fatigue. Doctors are helpless, tried almost every medication available.