"but i do feel like he needs someone to be there constantly since he is not making the best choices on his own i feel like i need to be there to push for him to make the right choices."
For me personally this was hard for me to grasp in the beginning but HE has a right to make those bad choices, he has a right to do as many drugs as he wants too it boils down to this it is HIS life to live as HE sees fit.
Now breathe a minute just because he has that right doesn't mean that what he is doing is OK but there is absolutely nothing YOU can do to make him stop you can't love it out of him if you could none of us would be here.
You didn't cause it. You can't control it. You can't cure it.
So what can YOU do well you focus on you and figure out why you choose to live this way. A really good book most libraries have it is Codependent No More by, Melody Beattie.
Read post here, post here yourself, check the stickies especially the one about codependency and what addict do.
That is a good starting point. Take what you want/need and leave the rest.