You did what you thought was right at the time. He is an adult but I know you never stop being a mother and will always worry, that's a Mother's lot I'm afraid.
Talk to your son, encourage him to keep a diary or write down a time line with important events on it, sometimes it helps to write down what you want to change or do. He may be reluctant to do any of this, that is his choice. You just need to be around if he needs you.
Just don't lose your dreams thoughX