I developed tnnitus in left ear years ago along with violent attacks of vertigo...Menieres Disease...
Tnnitus can be caused by a whack of different issues including seasonal allergies, BPPV, fluid build up in ear, infection, stress, Menieres...etc. ENTist will probably perform a few tests to rule out Menieres or another chronic condition but from what I have learned over the many years dealing with Menieres, that tinnitus is usually brought on by allergies.
Good luck and hope you get it sorted.