Is refusing to let the police search me an admission of guilt?

No, you have an absolute right to tell the police that you’re not going to consent to a search. The Fourth Amendment protects against unreasonable searches and seizures, and absent some type of exception to that, the police are not supposed to search you. Now, if you do consent, and they find drugs or some type of other contraband on you, just because you consented doesn’t mean to say that you’re not going to get arrested. In fact, if you’ve consented, and you’ve allowed the police to search you and they find things on you, something illegal, you’re going to get arrested. So if you’re not doing anything wrong, don’t consent. If the police have some other reason to search you, you can challenge that at some future point when the court takes a review of your case.