I think it is very likely to be MS-related, and not paranoia.
Buzzing or vibrating sensations are a very common symptom - although they can be anywhere, and not necessarily in the ear.
The reason exact symptoms vary so much from person to person is it depends exactly where the lesions form - which is pot luck - and what parts or functions of the body that little patch of brain is responsible for.
So although you often see buzzing/vibrating reported, some may have it in a foot, some a finger, some an intimate area, or some an ear - or anywhere else you can think of!
It is hard to know if it’s a relapse. Have you got any infection at the moment - even a minor one like a cold? This can be quite notorious for prompting a temporary increase in symptoms. Or have you perhaps been overdoing things? Stress and overexertion can also prompt an increase in symptoms that could be mistaken for a relapse.
It’s probably a good idea to report it anyway. Not because they will necessarily decide to do anything about it, if symptoms stay at current levels. But because it’s a good idea to maintain a formal record of known or suspected relapses, as frequency and severity of relapses could influence the type of treatment you may be eligible for. An unreported relapse can’t count!
(I am absolutely the worst at taking my own advice - I don’t usually report a relapse that’s only a “maybe” - especially if I think I may have had a cold or something to account for it. But I know I should, really…)