Changing careers at 11 years into a job, is it realistic?

After 11 years as a security officer I am thinking about moving into a different field. It has been weighing on me all week. My family is supportive but nervous. How did you start?

You likely have more transferable skills than you think. Write down what you did, not what the job title said.

Thanks for writing this out. I went through something close to it 6 months ago, and it settled down once I kept a simple log of every call and form.