You are tired all the time because of the pain. Pain is so exhausting, particularly pain in the head. Also, if you are clenching and/or grinding your teeth at night (and it sounds like you do), it means you are not getting the proper amount or quality of sleep that you need.
I hate to say this but must - x-rays really won't tell you definitively that you have tmj or not. Tmj is very complicated and involves the joint cartilage disc, muscles and tendons all around the joint(s). You might be clenching your teeth at night because of stress. X-rays aren't going to show that sadly. But an mri might show your disc out of place but again, many people do and have no pain.
But don't despair. It's not all doom and gloom like I make it sound. I am not a doctor, just a fellow tmj sufferer who has done a lot of research. Your symptoms do sound like tmj. Of course you should be checked out that it's nothing else, but too frequently medical people know nothing or little about tmj and you'll end up wasting time and money on tests and appointments, etc. Do all the research you can so you will be educated and knowledgeable.
I do have a concern about you saying you are getting braces. Please get your pain under complete control before contemplating braces. I was in pain 24/7 when braces were put on me. Big mistake. I stayed in excruciating pain the entire time and came out of the braces still in pain and with damage to the joints.
I highly recommend that you find a good tmj specialist (dentist, etc.) who will address your pain. Usually that means a bite splint for approximately six months and then maybe braces. I have to stress, though, that the purpose of your braces should be to balance your bite, not necessarily straighten your teeth.
This is a very complicated situation even though it shouldn't be. Tmj is basically pain caused by an imbalanced bite/jaw. Why the imbalanced bite/jaw, though, is the difficult question to answer. Keep this in mind when you start any treatment plan (and braces can be part of a treatment plan). Also think of your quality of life. You do not want to be in pain all the time. Plus and I don't know if I can get this across - if the pain is not taken care of, it usually means what's causing the pain is not being taken care of, which mean damage is occurring and if it keeps occurring, permanent damage may occur and you could end up with tmj for a very long time. Does that make sense?
Tmj is "curable" or manageable, but again, you will need to research tmj, know your symptoms and prayerfully make the right decisions to your treatment. Think about what makes sense. Take time and don't make any hasty or emotional decisions. Surgery should not be considered because of the high failure rate. Braces should be considered but not placed in your mouth until your jaw is stable and free of pain.
I do hope and pray that all of this makes sense to you. I can't stress enough about knowing what tmj is because of doctors and dentists just don't seem to know or even care to know. It's pretty sad. You have to do what's best for you.
Please excuse all typos, etc., it's late and i'm not going to proof read. Sorry about that.
God bless...
Carol