B.C.
You just had your daughter 13 Months ago?
That's over a year and plenty of time for adjustments.
That you are having hot flashes really points to a hormone imbalance and it could very well be peri-menopuase - my peri-menopause lasted more than 10 years before I was in full menopause at 51 years old - and that wasn't early.
If this doctor isn't listening to you or is not taking you seriously - fire him and get another doctor.
Taking home pregnancy tests one after another is not giving you any answers.
No one on the internet can tell you what is going on.
Anxiety can have an effect on your hormones so if everything else is testing out as normal then it's time to get your anxiety treated.
6 months on a low dose of Zoloft might do you a world of good.
Additional:
If Xanax didn't work out then try a different med - keep working with your doctor.
Sometimes a medication really is needed - it just make take some time to find the right one.
You go from flailing and anxious in your post to it's-not-so-bad in your SWH.
That sounds a little bipolar - just keep working with your doctor.
Parents have some parenting experiences and advice but we're not really a support group for complex situations.
It's important you get the kind of help that will be the most helpful for you.
Not that you are but if you happen to be a 'grad student' posting made up stories so you can harvest / data mine experiences find something better to do over your spring break.