When there is considerable numbness present, taking B12 initially may wake up sleeping neurons and give the appearance of worsening. Also try to eat high potassium containing foods...as beginning B12 supplementation can rob the body of potassium as the bone marrow makes more blood cells.

Yes, I would change that BP medication to another family of drugs. If you supplement magnesium, you may find you need less BP medication, as fixing low magnesium can lower elevated blood pressure by relaxing the small blood vessels. Do not use magnesium oxide as it does not dissolve in the GI tract and therefore does not provide absorbable magnesium for you.

Make sure you take the methylB12 on an empty stomach for best absorption.

People really vary in regards to hormones. Some find them helpful and others not. Using bioidentical estrogens may help with your side effects. Usually they are provided in a transdermal cream. Just Google "bioidentical hormones", to learn more.