Hi there

I'm a 20 year old male. My problems started about 4-5 years ago.
I was making pressure inside my mouth (holding my nose, closing mouth and breathing out hard) to relieve clogged up ears
While doing this I suddenly felt a slightly painful popping feel around the jaw area below the ear.
Since then my jaw (left side only) have sometimes locked up while yawning, and quite often a sound is produced from the joint when opening and closing the mouth. It's sounds kinda like some sort of soft tissue is getting squished. Moving the jaw sideways produces the same sound.

It's not really painful except when the jaw locks up, but that rarely happens any longer. The squishing sound is extremely annoying when chewing though, and I'm worried it might get worse.

Any ideas what might be wrong?