Anything I share is just my opinion...

Moving back in with your parents may not feel ideal as it may present problems of its own. You will be safe, though. Your own journey of healing can begin...

The friendship might be on hold for awhile. It's obvious your buddy means a great deal to you.
Please allow yourself to grieve over this situation. Anger might also be a part of your grief...and that is okay. There's bound to be a variety of feelings surfacing now that you are taking care of yourself. Go with the flow, face them, and move on.

bpbruins, perhaps it's not that your buddy won't listen but that he can't hear you. He's in his own private hell and it's hard to hear the voices of concern when you are in that hell.
I heard only echoes of concern and didn't give a damn about them. However, the seeds of love and caring were planted in my heart. It took time for them to have any impact on me...I was hell bent on living dangerously.
I now understand it was passive suicide. Obviously I survived my intentional suicide attempts. The next "best" thing was to live in a way that would open the door to oblivion.

Concentrate on you. Heal.
Beat a pillow when--not if--you are p*ssed off.
Weep when the need arises.
Accept you did your best but he was not ready. It's no reflection on you and your efforts.
Guilt is not allowed; it's a waste of energy and can suck you dry.

Good luck as you start on your own path to peace.

Catherine