Professor Aaron Kay found that when we see someone as passionate about their work, we see it as more legitimate to exploit them.
Every coach -- but especially young coaches -- should read this article.
Short version: if you are passionate about what you do, there will always be employers looking to take advantage of your passion.
Your passion makes you more valuable, not less. If your gym doesn't treat you well, you can be just as passionate somewhere else. Never lose sight of this fact