I think that individuals' reactions to psych med's can be quite different. I'm no longer on anything. Nothing I've taken ever really did much good. But, when I was on med's, I found that one med, mostly antidepressants, was all I could tolerate; & even that put me in a fog. When I see the lists of medications many members, here on PC, are on I think: wow... if I was on all of those med's, I'd be comatose!
Of course, depression itself also is fatiguing. So it's difficult to say if what you are experiencing is a result of your depression or the medication. One thing I have experienced is that anytime I would see my pdoc, if I said I didn't feel I was doing well, he would automatically want to increase the dosage of the med I was on, or add another one. Had I agreed to it all, lord knows how much medication I'd be on at this point...