What is wrong with my ear???

Alright so my ear has been doing this SUPER weird thing lately for maybe a month. If I burp or yawn or sometimes it is just random, it will drum roll?? Thump??? I don't know how to explain it. It feels super weird and honestly uncomfortable. I can't say that it hurts when it does it but it hurts in general sometimes. I have been to see the doctor twice. Currently on my second round of amoxicillin because the doctor figured the first round wasn't strong enough. She did say the ear was red inside. I have no idea what is going on with it. It was getting better the first couple days after I started the medicine, however I was sleeping with a different pillow then? I don't know if that can make a difference but it is definitely something with pressure changes around my ear. Any insight would be extremely appreciated! 

I should also mention that I grind my teeth pretty bad at night. So bad that my retainers are all shaved (especially on my left side which is the side that the ear is messed up)

I have the exact same thing since late spring.I been taking allergy pills to calm it down,but if I burp or yawn there goes the thumping and rumbling and me being sleep deprived all week on and off.The doctors don't know what it is.They think I'm crazy cause they never heard of this before.So I just have to wait for it to settle like always and it stops for a while for a week or two then back to thump land like right now.