Smarie.....He will be back. lol...I don't even know him, and I would bet my kid's milk money on it.
What will you do when he is back? Can you get the land lord to ban him from the building...and the property?.Tell them he is a menace to you.
Tell your neighbors to call the landlord if they see him. The landlord can have him removed for trespassing (not necessarily arrested..unless they can find grounds to do so). The landlord may have to sign a form, in advance.
If he comes to your back door..you can call the police, and they will remove him for trespassing on the property. If he knocks on your door..you know who is knocking..you know his voice.
(I did this, myself, for my adult son (for his good and my good).....
Put a big sign on your refridgerator, that says: HE HAS A PLACE TO GO!
In the meantime, your place to go is to your meetings and to the therapist so that you can get back in touch with yourself....if not---it is virtually certain that your next couch may be soaked by urine from another soul who is seeking an enabler.
These guys are a symptom of your disease...of some pain inside of yourself that is not, yet, healed......