missed period

Hi everyone. I'm about to be 25 years old in a few weeks. My period is
extremely late. The last one I had was at the very end January. I
haven't had sex since around July. I've have gotten a period each
month, not little periods extremely miserable, extremely heavy. Now
It's already March. I had two really close together. I had one at the
end of December and one in January. I tend to miss periods when really
stressed. In early Jan, I was in a bad car accident. I was in an SUV
rollover. I had back contusions and everything, and my boyfriend that
I was in the wreck broke up. The insurance calls and college is really
stressing me out. I know there is no way possible that I'm pregnant.
I'm having severe cramps as well. They are not low, they are really
high up at the top of my spinal cord. My vagina is very dry, like I'm
not even producing any hormones. I was down for a month, with hardly
no movement. I gained alot of weight after the car accident and break
up, about 25 lbs.I took alot of muscle relaxers and pain pills after
the accident, and I'm off then now but, I do take medication for
bipolar disorder. I think it could be a combination of meds and
stress. Give me an opinion.
Thanks!
Bri