Tooth ache worsens with position of head?

[MountainMama]

So I am so confused about my cracked tooth. I have had so many conflicting symptoms with this tooth (including being unsure if the tooth was actually cracked). My dentist originally said it was cracked after elimination of other diagnoses. Then at my last appointment they said they saw a crack on the 3D x ray and we scheduled a crown prep, which is now delayed until who knows when.
They tested it and said the nerve was fine. I had a lot of aching in my jaw, which subsided after my nightguard was adjusted.
Just last night, I started having a more intense ache that would intensify then fade. The weird thing is that it gets worse when my head is down, or I lean over or tilt my head. Could it be related to my jaw muscles? I have been feeling like my jaw is tight right now.
Aaagh! Right now isn’t the time to have more pain crop up. I almost just want to ask them to extract it because I am so tired of this.

 

[Gordon]

Could be sinus issues, they're very commonly related to head position. Or it could be your jaw. Sorry not a great deal of help there!

 

[MountainMama]

Could be sinus issues, they're very commonly related to head position. Or it could be your jaw. Sorry not a great deal of help there!

That’s okay. I appreciate you responding. I think just having hope that it could be my jaw would be nice. I don’t think I can handle having a tooth nerve flare up right now with the dentist closed.
I do have sinus issues right now (allergies), but this is a lower tooth which wouldn’t be likely to be affected, right?
I really hope it is just my jaw. Stress is high right now, obviously, so I have been back to clenching at night. I woke up doing it last night, biting hard on my nightguard.

 

[Gordon]

Yeah, lower teeth won't be affected by sinus issues, sorry.