Lily, I have heard recovering addicts say the really end up "hating" their enablers. His mother is doing the hardest thing she will ever do, stand by her and support her. You can and probably will have other BFs, but he is her son...irreplacable.
Like I was, your love has become very selfish. If you truly love him like you say, let him fall now! Until the pain off using outweighs the fear of stopping, he wont stop. Let him feel the pain!! Give him a chance to seek recovery.
Trust me, I know how difficult this is. I wish I had known this a long time ago. I wish I had known how selfish I really was! My thinking was about HIS addiction was hurting ME, can you imagine?? ughhhh