fatigue

I was diagnosed with breast cancer 7 years ago aged 33 , had 8 sessions of chemo, a bilateral mastectomy and lymph nodes removed, followed by various reconstruction operations, was on medication to stop my periods, went through what I thought was a menopause, then taken off the meds, periods returned but really haphazard  . My mum passed away in 2003 after contracting MRSA after breast reconstruction. I have pains in my knees, toes and wrist, have had three ops on my wrist, none have helped. I  now am suffering really badly with fatigue, sometimes it doesnt take anything to make me tired, sleep doesnt help. I dont know what to do, have had various blood tests, all were ok. No one seems to be able to help me, really frustrated and making me depressed. I am on meds for depression and anxiety.