For the last four days, when I try to close my jaw/bite down I am not able to all the way. It doesn't feel like something is blocking or obstructing the way, but rather the muscle being stressed to the point that it can't flex any further.
I think the bottom part of my jaw (bottom row of teeth) is pushed forward or something. I haven't had any trauma to it that I know of. I am not able to close all the way because the front top teeth start rubbing against the bottom front teeth and hinder the jaw's closing. To explain further, If I try very hard to bite down I can, to a point. I pull my bottom jaw back with no help from my hands and bite down very hard. My jaw muscles feel very tense and stressed when I do this. Also, I have been for the last four or so days, feeling a soreness and tiredness from my jaw.
When I was about twelve years old I had a bike accident and landed on my jaw. My jaw didn't break or anything but it did break the skin resulting in the cut being glued (some type of skin adhesive) closed by a doctor.
Since then when I eat something chewy my jaw will quickly become tired and sore resulting in me having to take a break from eating that item.
I hope I am explaining it properly. If you have any questions, please don't hesitate to ask.
You're experiencing temporomandibular joint tightness. I am a former dental assistant and have been experiencing the exact same symptoms. But I slept with my cheek on the back of my hands (odd, I know), which I'm sure is the reason why my joint got out of alignment. All I can suggest is that you see your dentist or a TMJ specialist. They can usually help with the discomfort by making you a custom night guard that will place your joint back into alignment.