Perhaps good old snail mail might come into play here?
e.g.
"Dear Dr Xxxx,
I am writing to you, rather than speaking to you by phone, as I am deaf and I know of no other way to contact you at the present time.
I have been taking [medication] for the past 22 years but Dr Yyyy, at Zzzz Hospital, has now stopped this medication. This is because I have been experiencing intermittent dizziness, which Dr Yyyy attributes to a reduced heart rate, caused by long term use of [medication].
However, despite this change, I have continued to experience dizzy spells, which I have found very distressing. If at all possible, I would like to discuss my problem with you on a face-to-face basis, so that I can lip read***.
If that is not possible, I would appreciate contact with you electronically (using my email address at the top of this letter) or by letter. Alternatively, perhaps you could direct me to someone else to whom I could address my concerns and who has the means to communicate with a deaf patient?
Yours faithfully . . . "
***or "with my friend present, who can sign for me", as applicable here.