Show up at your court date and talk to the prosecutor. Explain the situation and ask him if he could help you keep this off your record. I'm not sure what they do down there in Austin, but in most places this matter would be "taken under advisement" or "diverted" or otherwise disposed of in a manner that would not result in a conviction.
You don't deny that you committed the offense (right in front of an officer), just that every else does not get ticketed like you did. In my experience, Austin city prosecutors only offer straight dismissals where my clients are obviously innocent and that doesn't seem to apply to you. It sounds like you have been offered the deferred disposition route by the State, which under the facts you have described, may be a good choice. You have the right to take this to trial, but I don't know that a jury would necessarily bail you out given that it was right in front of the officer.
Contact a local criminal defense attorney to see what advice they would give you and what they would charge to take this case to trial.
Disclaimer: This answer is provided as a public service and as a general response to a general question, it is not meant, and should not be relied upon as specific legal advice, nor does it create an attorney-client relationship.
I agree with my colleagues.
If the prosecutor is willing to offer a pretrial diversion or deferred adjudication in exchange for community service, you may be able to get credit for the activities you are already participating in.
You may wish to consult with a local criminal defense attorney for a more in-depth analysis of your situation.