No, you can't get fired. The administrators have shut that feature off. Much to the chagrin of many of us.
But one bad season wouldn't have gotten you fired anyway. In the past, when coaches could get fired, it was usually for at least three bad seasons. Though it's been so long ago I don't remember. And it was different for every team, based on what kind of team.
The advice above is good. Red shirt three players every year. I took over your Florida State team, and you didn't red shirt any players there as well so maybe you aren't aware of this feature of the game. Red shirting players is a major way to develop your best players. As well, you can change the formation of the team you are coaching. Especially if you plan on coaching the team long term.