Yeah, my friend, you are in some hot water. Go to a lawyer. If you are truly at the low income level try legal aid.
The city, state and federal governments are so desperate to raise money they are truly seeking out unregistered businesses. They find you either by a complaint or craigslist or by your website if it shows up fairly easily on a search.
The first advice I always give EVERYONE is to get those legal documents making you a business!!! If you make nothing, then you're only out MAYBE $50. BUT if you are found to be in business and haven't done your legal stuff? You can be held liable for the amount of taxes the AVERAGE photographer should have paid for the time that the gov't and subsequently the courts find you to have been doing business illegally. Not to mention any penalties.
There are so many loopholes that an attorney can guide you through and GET A BUSINESS CERTIFICATE/Tax ID.
FL Dept Rev - Florida Sales and Use Tax
I know I sound like doomsday, but an attorney can help you. DO NOT try to talk with the gov't yourself. It's so easy to incriminate yourself without saying anything it's not funny. That's what they will be trying to do.
In the mean time you need to get together your receipts for EVERYTHING related to doing business-print orders, equipment purchases, gas to and from shoots, vehicle expenses (it's only a little business, but your attorney will help you with it), computer software, computer hardware, even your electric and everything and then have an attorney and accountant guide you on how much can be deducted as a business expense. That will help to reduce what you owe as your actual "income" will be less. You will also need any record of ANY payment received from any customer. Paypal, bank, receipt book... whatever you have.