I know this will sound trite. But you just have to learn to let it go. It is just a job. And yes I understand pressure from work, but I have learned that it is just a job. I have family, friends, children, fur and human and lots of fun to have. I refuse to let the job make me nuts.
Go in, do your best and leave it behind.. Much harder said then done, it takes practice but it comes easier with time.
Try to have someting to look forward to when work is done, EVERYNIGHT.
Makes a world of difference.
Best of luck.
Oh and if your boyfriend is being a %ick about your headache, time to get a new man who treats you better.