Missing money from impounded car; should I withdraw complaint?

I recently had my car impounded. When I got it back, there was a hundred dollar bill missing from the glove box. I told the officer who was with me and he had me file a report. Afterwards, he told me that if I was lying, I could be charged with a felony. I don't want to have to fight felony or obstruction of justice charges. I don't think its likely that I will get my money back either way, not do I think that its worth the time to try. Should I withdraw my complaint, or will that just make things worse?