Hi jpnme,
My son, Michael, is also addicted to heroin. I remember when I first found out, it sent my world into a spin.
You have found a good place here at SR.
There are many parents in your same situation.
I guess the hardest thing for me to learn was that I can't fix this for him, no matter how hard I try. It's something that they have to decide for themselves. It sounds as if your son has chosen a good path. My son is currently clean, living in a 1/2 way house and working, not because of all the things I tried to do to 'help' but because he decided to fight his addiction.
You did not cause your son's addiction, nothing you did 'made' this happen.
Take a deep breath if you can, things will get better for you. Here at SR you will learn tools to help you with this.
Like you, I love my son very much
Welcome to SR,
sigh