Weakness in entire body

About 5 years ago I've been extremely weak all my muscles especially the joints have been hurting. It gets so bad that sometimes I can no longer walk or move the doctors say I have nothing, but that's not possible if I feel the pain. The pain is not always present but it gets worse when I get colds. I also have respiratory problems in where I can't take a full breath, I've gotten chest x-rays and nothing, buy I am constantly wheezing. I've been tested for lupus as well juvenile arthritis and all has come back negative so I've become extremely desperate and no longer know what to do.