There are plenty of career opportunities abroad; you just have to know where to look. Teaching vacancies can be found in a diverse range of countries, and in particular, China, Japan and Thailand are crying out for English speaking professionals.
English speaking countries like USA, Canada and Australia can be easier countries to settle in to, and there are plenty of opportunities here, depending on the job role. Take Australia as an example, they release a skilled occupation list, and if your current skills match to an occupation on the list, you have a better chance of success when you’re over there.
If opportunities are hard to come by in the UK, then there’s no harm in looking for jobs further afield, but of course moving to a different country will change your life entirely, so you shouldn’t necessarily rush in when making this kind of decision.