Hiyer, it could be something really simple like anaemia....which causes your symptoms.....but you definitely need some blood tests done and a general check of your vital functions. You don't mention having had chemo, but you possibly might be on hormone therapy...which might also need considering. I've read other people say though, that we need be careful about presuming everything healthy is is related to BC, especially as you are 5 years since treatment, it could be something unrelated. Please do go and get checked!
Have you discussed this with your gp? Don't want to be alarmist but there are other threads on here in 'recovering from treatment' and similar symptoms have turned out to be related to heart function (as a result of treatment) I'd really want to get this properly investigated if I were you x
I am nearly 5 years post lumpectomy & radiotherapy. Yes, I am overweight - can't seem to lose no matter what - but my stamina is appalling. Cannot walk, talk n breathe. Carry the washing upstairs n heart is thumping....any views? 😮