The first thing you should do is stop placing facts of your incident into writing. This may be used against you. In this posting you made several dangerous admissions. I strongly suggest you hire an attorney and if you cannot afford one to make an appointment with the public defender immediately.
Obviously it would help you if you can afford to retain an attorney. It is very unlikely that your post could be traced back to you, but it is a good idea to refrain from talking about the specific facts of your case. The first step in the process is a preliminary hearing. At this time, the Commonwealth must present some evidence to support the argument that you were involved in drug distribution. This burden is not difficult to meet. However, based upon the facts that you presented, I believe that it is a stretch to say that you were involved in a conspiracy with the drug dealer. Merely knowing where an individual can get drugs is not enough to establish a conspiracy
Criminal conspiracy is defined in 18 Pa.C.S. § 903 as follows:
"A. Definition of conspiracy -- A person is guilty of conspiracy with another person or persons to commit a crime if with the intent of promoting or facilitating its commission he: (1) agrees with such other person or persons that they or one or more of them will engage in conduct which constitutes such crime or an attempt or solicitation to commit such crime; or (2) agrees to aid such other person or persons in the planning or commission of such crime or of an attempt or solicitation to commit such crime."
He there does not appear to be proof of an agreement between you and the dealer. Therefore, I would anticipate arguing that there was no overt act establishing a conspiracy between you and he. At worst, this looks more like you and a friend buying some weed together.