Welcome!
Are you a Canadian citizen as well? If you are, then your ancestry can help you in your quest to become British. If you're American, your options are limited to work or study (as you're already married), and study doesn't lead to citizenship.
Work will be a tough one for you as a writer; unless you're an internationally acclaimed name, there's no real way to get a work visa for writing. Your best bet would be to look for a US-based company with offices in the UK so you might make an intra-company transfer when you have enough seniority.
Good luck, it's not an easy trip but it's very rewarding!