Do I have any chance of keeping my license?

You certainly have a chance of of prevailing at your DOL hearing but in all likelihood you'll need an attorney to assist you. There are a number of issues based on your brief recitation of the what occurred. Whether the arrest was proper after a .023 PBT is one. Was the stop lawful is another. Certainly the timing of the blood draw in relation to the stop is something that needs to be investigated. But to fully have your case analyzed you'll need to sit down with an attorney so he or she can review the entire police report. If the DOL has already scheduled your hearing and you don't have counsel, the report should have been provided to you by now.

If you are planning on proceeding pro se, you'll need to focus on the four issues that are the subject of the DOL's ruling. Were you under lawful arrest? Were there reasonable grounds to believe that you had been driving under the influence at the time you were arrested? Had you been provided with your implied consent warnings? Was there a valid BAC of over .08? But proceeding pro se in this arena is very difficult and rarely successful.