I would be pretty sure that you are still experiencing effects from the chemo. It can take some time to feel good again. I was still experiencing those symptoms at that stage of things. I remember feeling very concerned about the muscle fatigue and breathlessness but it was just the chemo and steriod effects taking time to pass.
Just give yourself time. I found it helped to find things that I could enjoy and do these as much as possible. Gradually the aches and pains lessened and life improved again but it is frustrating because you just want to feel good again. Hang in there, better times are on their way. Deanne xxx