Mike,
No shame in that. Just starting out in wood restoration, most of us have taken more than one little no profit, or evem loss jobs. Comes with the learning territory.
One trick is to carry a few strippers when doing estimates. 1st, it is easy to tell if you have a potential nightmare. 2nd, it becomes easy to know you can do the job with the knowledge and chems you know. 3rd if you are good with mostly clueless competitors, you can get well paid.
Wood restoration is a lot different from house washing or concrete cleaning. In the right customer market, not price but quality oriented, it can be a good seasonal business. Get good and experienced, especially on difficult jobs, and you can do well.
Hard part is you have to charge for the experience, knowledge, and effort. Takes a while. But you will become more than worth it.