My mum started pursuing acting in her 40s and has made an okay career. Not enough to quit her day job (freelance bookkeeping) but she's done guest spots on Casualty, Doctors, all those shows, a few TV commercials, and loads of fringe theatre (but at well-regarded London fringe theatres whose productions get reviewed in the national press, not pub fringe).
Being in London or a major city is pretty much essential to pursue acting professionally. But if you want to do it, DO IT!! I don't know why people are tearing you down for having dreams, do people think the OP is imagining she'll be on set snogging George Clooney within a year?
If you only want to perform or get a feel for it, amdram can be a great way to go. Though scope out what amdrams you have locally, because some can be dire (the kind where the same people always get the leads regardless of talent or being within 40 years of the right age range, you know the kind of thing). Or explore acting classes like evening classes, even decent community colleges might do acting evening classes.
Becoming a professional actor is extremely difficult and requires a lot more than being emotional and inhabiting a character. 99% of the work is not playing characters but all the other stuff, like showreels headshots and auditions. Audition technique is different from good acting. So perhaps amdram would be best; only you can know.
Alternatively have you ever considered writing? An ability to invent characters and mentally inhabit them is absolutely the quality you need to be able to write (more so than acting, where you play characters someone else has invented and play them the way a director tells you) and anyone with a bit of spare time and a pad and pen/laptop can write something, it doesn't take the special training and pricey items acting requires.