Can TMJ go away without treatment? What can I do?

I am pretty sure I have TMJ, however it's only been 5 days.

About 5 days ago I felt my jaw "popping" it was quite strange. It did it all day, and for 3 days after that. I mentioned it to friends.
I looked up Jaw popping on the internet, didn't read much about it but it said to be careful yawning. It's only on my left side

On the night of day 4, I started to get a pretty serious headache. I can feel it in the back of my teeth, my left side temple and behind my eye. I woke up with the same symptoms on day 5 and it hasn't stopped since.

My mouth can't open as far as it used to, just 1.5 times the width of my finger. It's hard to chew and eat without pain. Not being able to open my mouth wide feels almost natural and no pain, as if it's not supposed to open any further. But I can't for example open wide enough to eat a burger without really concentrating.

So I researched more online for a few hours and all signs point to TMJ. I keep running into post after post about people having pain for years. And I don't really see any for sure cures, nothing that says it'll go away in a few days or even weeks.

I'm wondering if there are a (majority or minority) of cases that go away by themselves without treatment? If so how long on average?

What medication should I take? Anything else i can do?

I should note that I am in Cambodia and Vietnam at the moment on vacation (now is Sept 9/11) and returning Oct 9/11.
The doctors here, I don't really have faith in treating me. So I'm hoping it will go away or what I should do before then. However the good news is (if available) I don't need a prescription at a pharmacy and can order whatever I'd need. Sometimes they have different names than North America.

Upon returning home if problems persist should I consult a doctor or dentist?

By the way, I am 90% positive I do not grind my teeth when I sleep. I have not had an accident, or gotten punched. No crazy chewing habits. I have no idea what could've caused this.

Thanks everyone!

This is all pretty freaky as it's just started and I keep reading about people spending the rest of their lives with pain!