Caught After Buying Marijuana

My question involves criminal law for the state of: South Carolina

approximatley 2 months ago a buddy of mine and myself were pulled after buying maryjuana. apparently the house was being watched and we were followed. they waited on him to go over the speed limit to pulls us, and when they did they searched the car. they found and 8th (3 grams). to make a long story short i was charged with simple possession of maryjuana and fined 565 dollars. this is my first offense ever although my friend has had some in the past. he is gettin a lawyer and his lawyer said i should say the weed was all mine instead of saying it was both of ours.(as we had originally claimed) so that he could get his charges dropped. now keep in mind i have never been in trouble with the law before(my whole fam is cops) i have court in about 7 hours and i have a few questions.

1) can i get into more trouble by going against what we originally had said and saying it was all mine? or fined more?
2) if so how much?
3) can i face possible jail time?
4) are there any other alternative besides PTI? because i read they have alot of fees in that program that i cant afford.
5) if i show up to court will they cut some of the fine out just for showing?
(i know they do for speeding, even though this is more serious just wondering)
6) im pretty sure i plead guilty given they got me with it, but do i say its all mine because his lawyer could just be looking out for his best interest?

Don't lie in court. You can go to jail for pretty much any crime, including lying under oath. Consult a lawyer of your own.

You don't get a special break simply for showing up in court. That's your obligation.

Ask a local lawyer about your eligibility for any first offender programs, assuming you are one.