I have right ear congestion (fullness)with tunnitus for 12 days that started as a short lasting ear ache, at the end of a 3 week cold. ?

Inner or middle ear: Have you checked out with your doctor? It might be worth doing so to make sure that there is no infection causing your symptoms

Eustachian tube: ET dysfunction from a cold can create ear congestion or a middle ear fluid problem that can cause temporary hearing loss and/or tinnitus . It usually will respond to medications that decongest such as topical nasal decongestants like Afrin or Neosynephrine; oral decongestants like Sudafed; and topical nasal steroids like Flonase, Nasacort, and Rhinocort, all of which are OTC. See MD if persists.