Should I quit or should I keep going

So I started with a dose of 50mg and I was on it for a month. I had terrible side effects for the first couple of weeks and then I was just... okay. After a month of being on 50mg, I met with my doctor and he gave me 100mg. I have been on 100mg for almost 3 weeks now and I don't feel any changes. I feel nothing. 50mg made me sleepy and 100mg is ruining my sleep, I can't fall asleep. Should I try to up my dosage or is it time to move on to another medication? I don't have any terrible side effects anymore, my appetite has been a bit weird but nothing too bad.

How long did it take for everyone to see some changes? What kind of changes should I even be looking for?