this is a lot to take in. especially if you had no idea, or even a suspicion.
coke addiction is a beast. altho your bf might be making the right sounds and even taking some action, it's likely to be a rough, bumpy road. plus there is more going on than he has revealed....there is always more.
his dishonesty, secret life, spending habits, lifestyle unknown to you are also out there now. and it can't get stuffed back in the box. the life you thought you knew with this man is forever changed.
whew. i strongly caution you to not get roped into being the $$ police. granted you need to do what you can to preserve funds. but being in charge of his allowance and doing forensic accounting on his expenditures is not healthy - you become judge, jury and prison guard. this is of course your choice, but with your lack of knowledge on the topic of addiction, and how unaware you have been of his drug use, it's really not the job for you.
it's really ok for you to call a time out - consider separating or spending time apart. if he wants help, he can find it in AA, NA, an addiction specialist, treatment, etc. i'm a former addict as is my partner - we found recovery independently of each other for the most part. i made the decision first, but my decision to quit did not rely upon him joining me. in fact i was ready to pack a bag and go and not look back. his path was slower to start and not all that smooth. it was all too easy for me to get snoopy, not trust him, be suspicious - and that is a hard mind set to get OUT of.
there is a lot good reading here to absorb. i hope you take the time to read the "stickies" at the top of this forum. head up on to the newcomers section - read the challenges and setbacks of those trying to recover. remember you didn't sign up for this and thus you are not OBLIGATED to stick around and try to help FIX it.