I am trying to figure out if I can do any DIY treatment that won't require me to visit a doctor or dentist, whether this means taking an over-the-counter medication or using another method.

For a couple years my jaw would pop whenever I chewed my food, but this only happened on rare occasion.
At the beginning of 2014, however, this started to happen more often.
About 2 months ago I experienced lock jaw for the first time- I was modeling for a drawing class and had to keep my body completely still for an hour, and when I was done, I realized I couldn't move my jaw. It took a couple minutes for me to finally move it back to normal.
I didn't experience this again until a couple weeks later- I bit into a sandwhich, and suddenly realized I could not move my jaw. I had a bunch of food in my mouth and had to sit there for a few minutes trying to figure out what to do...
Eventually I managed to move my jaw open with the help of my hands massaging my joints, and for the rest of my meal I struggled with a jaw that would lock into place with every bite.
The rest of the week this did not occur, however. It came back about a week later at breakfast, and luckily this time I could part my mouth about an inch open whenever my jaw locked so I could chew a little bit.

From then on this has been very common. Sometimes it happens every other day, it is very random and only happens when I am eating food. I have noticed that it is only my right jaw joint that locks, and usually it only locks so that I can't open my mouth wider than an inch. It is very easy for me to move my jaw back into place, but it is very annoying and takes much longer for me to chew. If I chew slowly I don't experience the problem but I'd just like to eat like normal again.

I don't experience much pain, it's just annoying that this occurs.

I have read up on TMJ, but what I don't understand is that I have never had any issues with grinding my teeth or clenching them in my sleep.
The only thing I can think of, is that I had braces four years ago, and had to wear rubber bands that would have moved my jaw.
I also experienced stress in the past couple of months because it was my second semester of college, and there was also a drastic change in my diet... But I'm not really sure if this could have affected my jaw this much.

I'd just like to hear some thoughts and suggestions from other people if they have experienced this or heard of this, and may know of some things I could do, even if it is as simple as taking vitamin supplements.
(I'm not currently taking any. The only medication I am on is birth control.)