Changing careers at 3 years into a job, is it realistic? - any advice?

After 3 years as a security officer I am thinking about moving into a different field. I would rather hear the honest version than the polite one. My family is supportive but nervous. Did you take a pay cut?

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