Why won't my guidance counselor just let me graduate a semester early?

In my school we do block scheduling. That means that we have four cles a day for 76 minutes until January than we start another eight cles in June. Each cl is worth 5 credits and a senior needs 140 credits to graduate. So, I already have 120 credits from my first three years in high school. I'm taking a full course load this semester, making the grand total 140 credits in January. The only cles I needed to take this year to graduate were gym and senior english, and I am currently taking both. So I should be able to graduate. I have all of my requirments done and I wanted to take off for the last semester so I can try some college cles and try working a few more hours a week at my nightly job. But my guidance counselor says that it's a new rule that seniors have to take a full course load all year because of our new superintendent. I'm angry because of this. They always told me that if I meet the graduation requirements, which I do, than I could just finish high school. I'm not dropping out, I'm really done. I plan to start college in the fall and the school I already choose said that they are fine with me getting some "real life experience" for six months. So how do I convince the school board to let me take the next semester off, one that I don't need at all.