Melatonin works best in a time release product. Fast acting starts to clear out in 4-5 hours and that can wake you up as falling levels are the mechanism of waking up.
Get DHEA-S tested. Some guys can get high E2 from DHEA-->E2 in the adrenals.
DHEA and pregnenolone are not very bio-available as they are not water soluble. Taking these with fish oil or other oily/fatty foods will improve absorption.
16mg x 3.5 is a very small weekly dose.
I do not see the reason to reduce hCG other than a perceived need to reduce hCG's ability to promote preg production in the testes.
Did you do pregnenolone labs before this?
Pregnenolone is made by mitochondria from cholesterol. Mitochondrial activity is regulated by fT3 as part of the body's temperature control loop. CoQ10 enables mitochondria to work properly. There is a lot of interconnection.
Have a look at the steroid hormone cascade here: https://en.wikipedia.org/wiki/Steroid_hormone
Pregnenolone has many important roles in the brain.