Been coughing white foamy then thick yellow blood tinged, now have severe sharp pain in left lower back when breathe in hard to breathe or even move?

Get checked: You need to get checked right now. You may have something as serious as pneumonia or a lung abscess, or even a blood clot; or something as minor as bronchitis with a chest wall muscle strain, but neither you nor I can tell, without an exam, X-ray and appropriate testing. Go to an ER now or call your doc now for advice on what best to do where you are.