I am a 20-yr-old who started experiencing jaw popping/cracking on the right side only about 1 year ago...TMJ?

I have not been diagnosied with TMJ. I was @ my primary care physician shortly after this began. He noticed I could not open my mouth very far. I told him about my recent popping & unability to open my mouth far enough to even eat a banana. He showed me an exercise-Applying pressure to the chin w/ your fist & opening your mouth slightly. He told me this would strengthen my jaw muscles and allow me to gain full ROM again. Needless to say, last summer went by and nothing got better. I went to my orthodontist at the end of the summer w/ several questions & concerns (I have had braces off for approx. 6 yrs, but still go because I wear retainers every night.) He told me to take NSAIDs, use heat, continue the exericse my primary care physician told me, & it should correct itself. Nothing better...I have been at my dentist twice since all this. I have trouble even opening wide enough to have hygiene performed...They said nothing! What do I do at this point? I don't want to live w/ this!