Well if part of your feelings for this girl are towards wanting to help her then thats not healthy at all mate, those relationships go sour quick, and end ugly. I can understand you still have feelings for the girl but you really have to realistic about this kind of thing, logical.

Ok so lets say she comes back and gets on your nuts. Now is this situation going to make it harder for you when she crawls to someone else when shes bored with you or are you just going to enjoy it for moment and let it go when it ends. Be honest with yourself, if this girl is a flake then dont even bother man, waste of your emotion and energy/money/etc etc.

The whole drug addiction thing is a big turn off for me personally. I try to stay away at all costs from relationships with those types of girls.

You need a girl who can fill in your weak areas and make you a stronger better person. Someone who you can benefit from, and not have to worry about what she is doing behind your back. Key to any lasting relationship is trust, honesty, love and understanding.

I know your only 16 man but learn these things early and youll be better off for it. Relationships that go sour are no fun, just causes bullshit drama, which you dont need.

Its up to you mate, your only 16, your gonna make mistakes, blah blah blah. Its not about the mistakes you make its about how you learn from them.