You are not the first here with a mess of hormone issues and a vegetarian diet. I see the problem as your diet, but nothing I can suggest will matter. I will be a shit-head and tell you that your choice may be hormone health or diet.
You can try pregnenolone, but that is a life long commitment. Pregnenolone is very poorly absorbed, so may not be effective. No harm in trying but even if beneficial, it may not resolve your problems. Cholesterol levels are one piece of the puzzle.
The other option then is [TRT and hCG to preserve your testes], or SERM. If you don’t use hCG with TRT, your pregnenolone levels could be reduced.
I also have to point out that there are some guys here who are carnivores that have idiopathic low cholesterol. They are here because, drum roll, their hormones are messed up. Unfortunately, we do not have lab work from any guys with low cholesterol who are normal, active and virile.
I think that trying a SERM would be a good idea. You can see how your body responds. You will want to have labs to see the before/after on TT, FT, E2, LH/FSH. If LH does not increase, your hypothalamus and pituitary are not working right. If LH/FSH increases but T response is poor, then the testes may not be working well enough. The testes will need DHEA as the raw material. When you add LH or hCG you need to wait a few weeks to get the full result as there may be bulk tissue changes[size and structure] that take time before you get to final form and function. If LH is good but T is not good enough, more SERM may lead to high amounts of FT–>E2 inside the testes and that cannot be controlled by anastrozole. If this all works, the testes might make more pregnenolone with the cholesterol that you have. And if this works, you can later try to taper off as in PCT, to see if you can get your HPTA to pick up the gun and run.
If higher LH from SERM or hCG dose creates larger amounts of T–>E2 in your testes, this might be a fix for your low E2. But anything that increases fT will increase fT–>E2.
In any case, you do not need to worry about foods with too much cholesterol.
Trying to get to 10% body fat may be very unhealthy for you. We see carnivores who attempt that who damage their hormones. Just because you think that something is healthy and validate your conviction with major efforts and changes; that does not preclude the possibility that it is totally wrong. If you want a better body image, fix your T and E2 levels and watch the changes.