Is the statement admissible at my preliminary hearing?
I don't think the admissibility of your statement at the preliminary hearing the real question. In fact, I don't really care about the statement much at all. The question you should be asking is whether there was enough evidence presented at the preliminary hearing for the judge to order that you proceed to trial and whether you (or your lawyer) should now file a writ of habeus corpus to quash the information/bills in the court of common pleas?
The answer is that your case should have been dismissed at the preliminary hearing and now you should file to have the bills quashed. In your case, no corpus was established at the preliminary hearing. Corpus delicti means body of the crime. In order for a case to proceed past the preliminary hearing in Pennsylvania, the commonwealth must establish that a crime occurred, i.e. the body of crime. While hearsay is admissible, there must be a showing that the declarent of the hearsay will be available to appear and testify at trial. If not, the hearsay is not allowed. If the only evidence remaining is the statement of the defendant, that cannot be used as the only evidence of a body of crime.
In your matter, there was no non-hearsay testimony from any person that you committed a crime. No testimony that the police observed you commit any crime. No testimony that the "victim" would appear for trial. No evidence of crime other then your statement. No body of crime has been established. Therefore, your case should have been dismissed at the preliminary hearing and now your case should be quashed.