I am thinking the work up that was ordered will rule out many things-
1) Hypo or Hyper thyroid.(temperature issues, palpitations, wt loss)
2) Perimenopause, which given your story, less likely but still possible.
Knowing when mom or sisters hit menopause can help here---
(Your hot flashes, insomnia could point this way)
3) The Esr will be a gross test for autoimmune issues...which can make you have dry mouth,eyes, and many of these other symptoms. If ESR high- let me know, I have a whole bunch of thoughts there.
But- I think there is an issue in your sleep-
AM headaches can be asign of sleep apnea, and with these night terrors, I would definitely want a sleep study. Sleep apnea usually occurs on the back!
MRI scan, huh? Well- itcan't hurt...unless it is costly for you.
Also- Headaches with nausea can be very common near meopause, so your labs will be telltale. The lower the estrogen, the more headaches (migraine) women get.
These type of headaches will give nausea, light and sound sensitivity as well.
So- rule out thyroid.
Make sure not near menopause by labs.
Check a sleep study given the terrors and AM headaches.
Check for autoimmune issues- Sjogren's gives dry eye, dry mouth etc.
You already have the ESR, I would add an ANA as well.
In the meantime, trial of a triptan medication for possible premenstrual migraine- which is much more common as we get closer....to that age! Go do the MRI , can only rule out worrisome things, could be related to nausea, and typically a tumor would not change your personality anyhow.
As far as the weight loss, the thyroid is the first to rule out- and if neg. perhpas a look for other causes. nausea may be related here- and after all f this, perhaps a look into the tummy with a camera....
Make sure your Mammo has been done, have your doc order a sleep study, and think alittle about how you feel about your sister's departure. Maybe something in that is changing your mood a bit?
So let's get that all cooking with the couple extra ideas, and see how it goes.
I have a hunch you'll be OK. Call it a gut instinct.
I will be around to answer any questions you have.
And- do something for you every day- that positive impact can be huge on our body's coping with anything!
I hope this was helpful for you--- Let me know how it goes!
My very best to you, and take care.....