He is an adult, time for him to take care of himself, your letting him live with you is enabling, it is not helping him one little bit.
If you do not take some action now, he will still be living with you at age 40. A 40 year old man with an emotional IQ of a 17 year old, unless he is forced to be responsible for himself he will make no progress.
Do you attend Alanon meetings? If not, might be a good idea.
I know this is a difficult situation for you and your family, however, it can improve if you will make the decision to take back the control of your life.
We are here to support you.