Have been taking nasal steriods for 2 weeks, still no improvement in tympanic membrane retraction and tinnitus. What should I do?

Get checked. get checked for both unresolved infection in both the TM joint and in the middle ear. Also check for biomechanical factors with the TM joint. These are the most common causes for tinnitus.
Get repeat exam. If you know your TM's are retracted a physician must have examined you. TM retraction and tinnitus can accompany sinus infections / "head colds" as the inflammation can cause obstruction of your eustachian tubes (which drain the ears). Your doctor likely put you on a nasal steroid to attempt to reduce the inflammation. If you have allergies adding an antihistamine may help. Other meds. can help.