Based on your details you have headache and nose bleeds ,sinusitis
can produce similar symptoms.It has to be confirmed by CT scan brain with paranasal cuts hence one can make sure the cause of it.
I feel leg pain while walking and lethargy can be due to blood loss, causing anemia. CT scan spine,blood compete count,platelet count
,clotting time, and prothrobin time will help to rule out bleeding nose secondary to hematological disorders.Spine scan will help to rule out degeneration of spine as MRI is contraindicated in your case.Consult Neurologist
and ENT surgeon (for local examination and endoscopy
) for clinical examination and further plan.