Well good on you, but I would remain sceptical I�m afraid. Don�t let a sense of guilt or benevolence keep you awake at night, worrying whether he might try again and only you can save him � nobody needs that burden.
How can you be sure this is not some unstable attention/sympathy seeking? I don�t mean to cloud any aspect of your post, but my senses would tell me to be very wary.
Like 4get I have had a friend and 2 uncles commit suicide and no end of support and love could have stopped them.