Would a sinus headache (it hurts when i bend over and my head feels stuffy) account for shortness if breath and a lightheaded feeling?

No: Sinus infection should not cause shortness of breath. The sinuses are in the face and head and should not affect breathing unless you also have nasal congestion associated with the sinusitis. But nasal congestion should only produce nasal obstruction and not shortness of breath. Light headedness is non-specific and is rarely due to sinus inflammation.