As someone with tinnitus and also sleeping difficulty I’m going try the melatonin
I suffered for 3 years with both Ménière’s disease and tinnitus. Absolutely hell on earth, my cure was daily B complex vitamins, low salt and 9 hours sleep nightly. I hope this works for you.
I was in the same boat -- tinnitus and borderline insomnia. To help with both, I have been taking melatonin for many years, 3 mg. Spring Valley brand, about 90 minutes before I go to bed. It definitely helps me sleep, and my tinnitus is no longer a significant problem unless I take ibuprofen, acetaminophen, or a few other things.
Another trick to improving sleep is to leave a fan on low in the room where you sleep. A little white noise can really help.
Good luck.