Dearest Mother, My heart can feel the pain in yours. How sad for you to feel this way. That you were not a good mother.
But....All is not lost... You have a son! Many Many do not. Your son is alive and you can speak with him. Many cannot.
If you feel that you have a more tender heart toward your son these days than you did in the past, let him know it. Show him, by your actions how you have changed! Apologize to him for the wrongs you feel you did to him and ask for his forgiveness and beg him to let you show him how much you love him and how many tender feelings you now have for him.
Do anything ....ANYTHING...to find that closeness you desire with your only child. Forgive yourself and go forward in a new Spirit and with the Grace of God in your heart you will find peace and love.
Your son is still young in many ways and you are also. Don't wallow in grief for a past that is over and gone. Take some action, kind and sweet action, to make the future years brighter for you both. Love to you, NJoy