Don't let anyone make you second guess a decision you made for your own emotional and physical health.
It sounds like you have finally had enough of the run around he gives you over and over again. He keeps pretending to go to college, lies about what is going on with his life, and his gf harasses you. He is 35 years old, you can't take care of him forever. He is a grown man, it is time he acted like it.
I'm proud of your for deciding to take your life back. It is really important to realize you have good things in your life, and it is great that you recognize that you do
It is easy to forget and overlook the good when dealing with an addict. He has made it clear how he wants to live his life, it is time you decide how you want to live yours.
Those in the meeting that told you your decision was "wrong" might just have been frightened by your strength. They are not in a place in their recovery where they could go no contact and hearing you are able to might make them feel uncomfortable. It is easier not to take action when no one around you is taking action. Don't let them make you second guess yourself.