I've had similar symptoms to you like the uneasy dizziness feeling & some preassure etc. & i've been diagnosed with a neck muscle tension/injury. I went to an ENT specialist as the drs thought it was my ears too & he picked up the neck injury. I spent months fluffing around with tablets for inner ear vertigo which did nothing for me & in fact one of those tablets resulted in me getting extreme anxiety & feeling crazy, i think it made my symptoms worse (was like stemetil). I've had a couple of accidents which have resulted in whiplash to my neck but even if you havent had accidents it can still just happen through bad posture or stress or anything. I still get worried about serious illnesses even though i've had reassurance from about 7 different drs lol.
I also suffer with extreme health anxiety which is causing those thoughts, might be what you also have? iI'm still dealing with my neck injury & still get the symptoms but i'm getting physio for it & doing excercises as there is a lot of neck tension. Might be worth going to a physio & getting them to check your neck out