I know the advice you are receiving is not what you want to hear. Each of us know and can say with certainty these things because we have been in your shoes in some way at some point in time. Many of us are still living what you have only begun to experience. I was the wife of an addict for 22 years. I wouldn't wish the pain and suffering that not only I experienced, but my four children had to experience, too, to say nothing of the suffering my ex-husband felt because of his choices.
No one can tell you what to do; any decision is yours to make, but please reflect on what has been said here. Read more posts from other members. Read and learn all you can about the disease and the affects of your partners disease on those around him - especially family dynamics should you ever marry him and have children. Please find an Al-Anon meeting where you can be face to face with other men and women with stories similar to yours. This is where you will find strength and growth. The strength and growth you find will help you answer your own questions.
This may seem silly at first, but when you are particularly worried or anxious repeat the three C's mentioned to you above: you didn't cause this, you can't control it, and you can't cure it -- not matter how much time and effort you put into him or don't put into him the three C's remain true for all of us.
Another one I'm finding that causes my anxiousness to calm is to deep breathe the Serenity Prayer:
God, grant me the serenity
To accept the things I cannot change,
Courage to change the things I can,
And wisdom to know the difference.
Please, above all, take care of yourself because the crazy train of addiction doesn't care about you and will run over all and everyone in its path without mercy.
By the way, someone mentioned you reading CoDependent No More by Melodie Beattie. I agree wholeheartedly. It was a life saver for me along with Al-Anon.
Hugs, keep posting