Overstressing Myself

I ended up giving myself a headache today.
Due to stressing myself out.

It was probably triggered when I realized I probably made a customer walk out of the store -deciding not to buy the things they were purchasing- because a) I had been stuck on register for a bit so couldn't help her personally with an issue b) told her she could get help from another coworker who ended up being busy -though I sent a second coworker to help her and then c) when I realized register was backing up and that she was waiting...helped a different customer first -cus that customer had been waiting in line first in a different line -and yah....I looked up from helping that customer to realize the one customer I'd been aiming to help...had vanished and I'm pretty sure she just decided her experience here hadn't been the best and bagged the entire buying trip. Y_Y 
Ooops.

I mean I can't make everyone happy. 
But oops. 

And like I had an ache behind both eyes which may have started around that point...an ache that indicated I was tired and needed more sleep.

So being in need of more sleep.
Then not being able to help that customer.

And then suddenly dealing with having to multi-task talking to a needy customer on the phone while I was backing up a rush at the register because literally I was the only person there to help out and I hadn't wanted the phone to keep ringing....*exhales*

I ended up overextending myself, stressed myself out more....and am now suffering the consequences.

I tried meds. A shower. heatpack. Sleeping. walking around the block. water. Etc.

And got my headache to the point of being faintly there.
But I feel like it's not going to go away tonight.

Hopefully it's gone by the time I need to get up for work. 
....but I'm rather doubtful of that actually happening.