Nicole,
there are really two issues here:

1. did you get some experience; some nice portfolio pieces and have a good time?

2. did they use you -- in the worst possible sense of the word "use"?

Only you can answer the first question. But what you answer will go a long of way in mitigating the answer to the second question which is: "yes, unquestionably."

Does that mean you're a fool? Not at all. If you gained experience and didn't lose any $$, then you had a net gain. If you also lost $$, then you got taken. So, make sure it doesn't happen again. In the long run, we all make "mistakes" on our way to figuring out how to make this avocation work for us. If this was your first, then accept it, make sure you understand what you gained and what you lost, and try to make the next experience work better for you. Because, in the scheme of things, if it doesn't work for you, it doesn't work at all. I do Rescue. I don't ever ask for anybody to sacrifice their professional abilities to my needs. If I wish to donate my time, I do it. My choice. Nobody manipulates me into doing it. And those that do should be avoided at all costs for all time. Period.

Jim