Middie, I am so so sorry for your situation!! I have as yet been unable to read your other thread. However.....
I can totally relate to your situation, as I myself walked in similar shoes....
#1 you take of you first!!!, then your baby!!!, and your other kids!!!
#2 he is an adult (I don't know his current, but from above, he's getting the care he needs!)
#3 live each day for and about YOU, take each step, one at a time, smell the roses if you like!

I think you've done extremely well, the way you're handling this situation, but I can't stress enough, you and your baby first and foremost.

My little (big) man recently turned 8yrs old, and still to this day....I was 40, the father was 41 (who I suspect has BP) when our son came into this world....his first child, my 3rd (my other two are 16 & 18.)

Do not feel guilt over another.....they ultimately must deal with issues themselves.
We can love and support (with steadfast boundaries) but we cannot fix nor be held accountable for their actions.
Big hugs to you, take good care!!