I would say it depends on how successful you are in your current profession. If you are employed with good, steady work and are meeting your income goals, you are taking a risk by embarking on a new career.
Things I have learned about the video business:
1. Never predictable.
2. Lot's of people with attitudes...usually it's the little local businesses who are the worst (being one of the only games in town really goes to their heads).
3. When looking for a job in video production, knowing your trade skills is akin to having all of your bodily limbs present- it's only the most BASIC requirement. What it really comes down to is WHO YOU KNOW.
I'm betting you really enjoy working with video, and that's cool. Here's what I would suggest: keep your day job -for now anyway. Start tinkering with Avid Media Composer, FCP, and whatever video camera you have -because you're right about being able to learn alot from experience. Then offer to videotape something for a charitable organization, or a school sporting event or something else pro-bono. It'll get your name out there, you'll get more experience, you'll feel good helping out, and most importantly- you'll find out if this is really for you. Do you need to go back to school full time? I don't think so. Taking a class or shadowing an industry person couldn't hurt though. I guess what I'm saying is you should put yourself out there for no other reason than you enjoy the activity, be weary of a huge investment of your resources at this point, and be prepared for a bit of a rocky start.