what about your ex education. is she a graduate? even the childrens should have willingness to study.
is your son good in studies? are you enquiring about it?
from what you say it looks like there is no family bonding for whatever the reason.
Are you still fighting for his custody?is there a chances of you getting custody of child if you have re-married?
But in present scenario, you are like stranger to your son as you are not having any communication with him. Will he come and stay with you all of sudden if you get the physical custody?
why don’t you try to communicate thru atleast 3rd party and try to build a good healthy relation (atleast now) and give him all the support what he wants as a father. years will pass fighting cases… forget the past and think about the future.