Changing careers at 17 years into a job, is it realistic? - 3 months and counting

After 17 years as a school bus driver I am thinking about moving into a different field. I have read a lot of threads here and could not find my exact situation. I have a little time and a small budget for training. Has anyone made a similar move?

I took a small pay cut for a year, and it was worth it for the growth afterwards.