Assuming they already got "the drugs", then yes, your admission would go a long way toward making you guilty. Words out of your mouth are admissible at trial, so jurors hearing you say "they're mine" in a drug trial would be a bad thing. This assumes your admission was voluntary.
On the other hand, if your question is whether you can take the blame for someone else by saying the drugs are yours, just forget about it. That's a bad way to handle a bad-enough situation.
I agree with Mr. Tillman. If you've already said out loud to the authorities that the "drugs" were yours then they will surely admit that at trial. There are some circumstances where the admission wouldn't be available, but they likely don't apply to what you're describing. What is most important is the context of what was said and how the witnesses (presumably officers) will present it at trial.
If you are able to hire an attorney, I would do so immediately. The best way to resolve your situation is with counsel from someone who can apply the law to your facts and review the prosecutor's file for you to see the best way to help you with this difficult situation.
If you are unable to afford an attorney, you can request one from the court where you are charged. I would do this as soon as possible because the courts often take your delay as a sign of disrespect.