The best advise I could you is for you to focus on you and look into codependency. Figure out why you fell so fast and hard for someone you knew had a history of drug abuse. Why this one person seems to have filled a void in you when the fact is he really has nothing to offer you because his addiction in one form or another will always come first and you will always be second.
When we use terms like....instant connection, haven't been together long but love them very much......it comes down to our issues not theirs.
You make a lot of excuses for his drug use, his past, his bi-polar, etc. and when we begin to do that we fall on the side of enablers.
He has to do what he has to do and if you are worried you will lose this relationship because he is in rehab then it's not a healthy one.