As per your description,it is tinnitus and possibly it's related to medicines(Cardizem) adverse effects.
Other possible differential diagnosis may include
Eustachian tube dysfunction
Blood pressure fluctuations
Your blood pressure should be checked.
Also try sleeping with your head propped up in an elevated position.
Try Valsalva manoeuvre
-Take a breath in. Then, try to breathe out gently with your mouth closed and pinching your nose . In this way, no air is blown out but you are gently pushing air into the Eustachian tube. If you do this you may feel your ears go 'pop' as air is forced into the middle ear. This sometimes eases the problem.
So you should discuss it with your doctor and if required a referral to ENT specialist can be advised.
Feel free for further queries. It's good to discuss rather than quit.
Your satisfaction is our goal.