Following causes to your symptoms....
Feeling severe cramp
at back of leg is indicative for possible deficiency in Magnesium
and vitamins. I suggest to measure the blood levels of:
- vitamin D
- lipids (lipid profile
(blood sugar levels)
Next, feeling nauseated and dizziness
is a sign of hypo-tension (as you fainted for a couple of minutes). I suggest to run cardiac tests to get further evaluated:
- holter monitoring
- cardiac echo
- stress test
- monitor your blood pressure
If everything is ok with your heart, then, everything you are experiencing is related to peri/menopausal syndrome. I advise to:
- drink plenty of water
- have chamomile tea at bedtime
Having "bad dose of nausea" (as you call it) might be related to:
- foods you have consumed (bad foods)
- cervical syndrome
- possible GI viral infection
I advise to take plenty of water with lemon juice. If no improvement, should consult you doctor for further evaluation.
Hope it was of help!