Yes, I have TMJ problems that come and go. Mine stem from nighttime clenching, which I've done my entire life, even as a very small child. I've never had pain come on suddenly, like you describe, though. Most of the time I have no pain, or just mild aching, but once in a while (usually during times of stress) it will flare up.
I wear a bite guard at night to protect my teeth and reduce the clenching (it's not possible to eliminate it), and during a flare up, I try to avoid yawning, eating foods that require serious jaw effort (or opening too wide!), and talking too much. I also don't chew gum, and occasionally rub Voltaren on the sides of my jaw. I got referred to a good TMJ specialist about five years ago and he gave me a couple of gentle exercises to do during a flare up, and he made me a bite guard where the weight rests on all teeth equally.
Also, beware TMJ specialists who tell you your bite is all wrong and want to make you wear an appliance 24/7. If they make you a bite guard and it changes the way your teeth meet, it may cause way more problems than it solves. I went to a specialist (the father of a friend) who did exactly that, and wore the (expensive) bite guard he made me for two days, but when I took it off I my teeth wouldn't meet properly and it scared me. I stopped wearing it. When I finally got in to see the specialist my dentist referred, he checked my bite and said it was fine, and said DO NOT wear something that alters your bite -- it's very hard on the jaw joint.
Bottom line: there are differing opinions on TMJ problems, for sure. I'm going to go with the method of the second specialist, who used non-extreme tactics, and who made my pain go away (completely).
I've also heard that yoga and meditation, or other kinds of relaxation therapy, can really help. I've never done this because it's not a priority for me, but if I had really intractable pain, I might.