Thumping in right ear, only triggered by sound

This is a strange problem and difficult to explain so please bear with me here. This has been happening for almost 2 years now.

If both of my ears are completely exposed, 90% of the time I have no issues. Hearing is even on both ears. The other 10% of the time, certain midrange frequencies cause my right ear to thump along with the sound and usually only when they're pretty loud.

Now the main issue is that 100% of the time, if my right ear is partially covered for whatever reason (let's say I'm laying down on my side and part of it is covered, if I wear a hooded shirt over my head, or even if I put my hand over my right ear slightly), the thumping happens along with the sound. So let's say someone speaks a 4 syllable word, I'll get a thump with each syllable. Or if I'm hearing footsteps, each footstep causes a thump. This seems to happen along all frequencies (except maybe the very high ones). The weird thing is the thumping doesn't happen if I completely seal my LEFT ear. It'll only happen if my left ear is completely exposed and my right ear partially covered. It doesn't even have to be covered all the way. I can put my hand about 5 inches away from my ear and it'll trigger this problem.

I unfortunately can't afford to go to a ENT right now so I'm hoping someone has an idea about what's going on here. One thing probably worth mentioning is I've had acid reflux for 4 years. I actually went to an ENT because of pain all on my right side....my ear, throat, neck and head. He did an endoscopy but said he didn't see anything there to worry about, and thought acid reflux is causing my pain so he prescribed me some Ranitidine which I've been taking since then (just stopped a few months ago though). It did definitely help the ear pain when I began taking it but I did still have reflux episodes probably once a month throughout the 4 years. I'm thinking maybe this has caused some ear damage but I'm really not sure.

I appreciate any help I can get.