Changing careers at 18 years into a job, is it realistic? - any advice?

After 18 years as an IT help-desk technician I am thinking about moving into a different field. Thank you in advance. 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.

Try a small project in the new field before committing. It told me a lot about whether I would enjoy it.