Google clerk where it happened. Get number for misdemeanor division of clerk's office. call them. see if they can send you a disposition report, if one still exists. If you got a nol pros, then the charges were dropped. You can petition to seal/expunge if this is the only incident in your life. Call or email with any questions.
You neither had adjudication withheld nor were adjudicated guilty. Adjudication withheld is when you are sentenced on a case (either from a plea or trial) but aren't technically convicted. Your charges were actually dropped, which is far better than a withhold.
This is not to be considered legal advice nor does an attorney-client relationship exist.
If you completed the program and received a nolle prosequi then you received neither an adjudication nor a which hold of adjudication. You case was dropped which is better than a withhold of adjudication.
Order copy of disposition from clerk if court and get it certified because you will need anyway if you seal or expunge
The very notion of your successfull completion of the Pre-trial Intervention program as you stated qualified you to receive a Nolle Prosequi, ie- no information will be filed and thus your case was dismissed. The court no longer has jurisdiction and thus has no authority to sentence you or make any findings.