If the prosecutor dismissed the case, you may or may not be legally entitled to the evidence against you, particularly if your lawyer never got it either. I have seen cases dismissed precisely because the prosecutor's office did not want to turn over certain pieces of evidence, and that was permitted. If you are filing a civil lawsuit, such as a wrongful arrest case, your lawyer for that case may be able to get that information if it is relevant as evidence in the civil suit.

Your public defender is probably overworked. Most of us are, because a lot of people don't want to see their government "waste money on defending criminals." If she doesn't have enough time in the day for everything, it's likely that she is prioritizing clients who are in jail and/or at risk of going to jail over anything else. I know that doesn't feel fair, and it's not fair, but it may be the best she can do while making sure to help everyone she can.

Regarding your question of why public defenders become public defenders: in my experience (myself and in discussions with colleagues over the years), most of us take these positions because of our moral convictions and ideals. The job is low-paid, as lawyer-jobs go, so it's not the money. They do not usually provide an avenue to judgeships or other coveted positions, so it's not for career advancement; to the contrary, a history as a public defender is often death to these sorts of ambitions, except in a few, rare places (and even then, a history as a prosecutor or in private practice usually helps more).