if its your first arrest, i HIGHLY doubt anything will come out of it as far as convictions. most likely you'll have to take drug classes and maybe community service.
right now, IN MY OPINION, it seems like your best bet would be to plead no contest (your lawyer knows better than i do, though) and get your friend to fess up to is being his.
but for now, just try to relax. i dont live in florida, but the chances of them trying to convict a first offender of a felony over some test (although its still in the same category as cocaine, etc, most prosecutors probably wont view it the same, but that depends, i guess) is HIGHLY unlikely. your lawyer will probably try to find a first offenders program or plea, you'll do the community service or classes, and upon completion the charges will be dismissed.
BUT MOST IMPORTANTLY... if everything does turn out like that, make sure your lawyer has your record expunged. i know in nc you can only have it done once (past 18), so its good to use wisely, and id say this is the situation where youd want to use it if you can (being a felony case). basically, it just means that the CHARGES wont show up if someone searches your record. otherwise, if you are offered classes and all that and the charges are dismissed upon completion, then when someone searches your record, they can still see that youve been CHARGED with a felony, even though you werent convicted. so, most people dont want future employers, schools, etc knowing that theyve been arrested and charged with a felony, even if it got dismissed, ya know?
just try not to worry too much. the jails and court system is so overcrowded theyre gonna want to get this out of the way (i know its a felony, but its not THAT serious compared to most any of the other felony cases are out there). youre not going to jail, you probably wont even have to pay the fine. i know im in a different state, but ive got friends who have been charged with felonious drug possession and gotten off pretty light (classes, community service, etc). but you just want to make sure, when its all said and done, assuming youre not going to get convicted (again, im not a lawyer, so i cant promise anything), make sure you get it expunged so no one can look you up and see youve been charged with a felony. because for most people, that raises a red flag, even if you werent convicted.