confused

Hi, I am so shocked that there are so many parents whose grown children have walked away no matter what reason.  I lost my father July 20, 2014 this year not to long after my oldest walked away from our family after putting his brother, sister, myself and grandmother through turmoil.  First i had to beg him to come to my fathers funeral.  
Then in went into turmoil over a possession from my mother he was fighting us.  The piece was finally returned after he told my mother to "F" off and never speak to him again.  In the process of all this, he was planning a wedding in which in the beginning he wanted me to help, then took everything away from me that I was to do.
 Proceeded to tell me how horrible his child hood was, kicked his brother and sister out of the wedding not once time but 3 times.  Him and his wife blocked everyone in our immediate family from social media.  He got mad when I sent him a sympathy card after he lost his birth fathers mother.  After we thought we were on talking terms again, 3 days before the wedding, he procedeed to tell me if I spoke at the wedding, I was going to be kicked out by his wife and father in law.  He feels in his head that me and his brother did not want him to get married, which was never said at all.  
Well I made it through the wedding without my hubby by my side, he had to go be by his fathers side during a heart surgery which was totally unexpected but thank God made it through.
My oldest, called weeks after the wedding wanting to stop by and get his birth certificate. When i came home he actually hugged me like he used to and we talked a little, but before he came to our home, I had left voice mails and texts on his phone with no response from him to come for dinner come and visit.  But never responded.  Well after he picked up his birth certificate- still no response with anything I have tried.  Now mind you, my husband of 20 years adopted him this year, because he had asked him to, we prayed about it for months, so my husband agreed.
Months prior to his adoption his birth father tried to reunite with him and we encouraged this relationship as well.  Well we were told how munipulating his birth father was, how his fiance did not like him at all.
So my son has walked away from me, my husband, his birth father and step mother, my mother, his brother and sister.  He walked away from the church and God 4 years ago.  Every nasty word that could be said has been said to me or my mom.
Now after all of this, still trying to grieve my father, I am realizing this may not just be my son's idea.  Which totally breaks my heart, we have always been about our children.  My oldest has chronic illness that I helped him through as a teen an young adult.  He was doing wonderful on his own.  course now he has dropped out of school, after going for 5 years, walked away from our family.  Guess all I can do now if pray, because any attempts of trying to communicate, I get no response at all.