Getting a visa to work in the UK is very hard. Unfortuately, secondary English teachers are not a shortage occupation, so I think it's probably not going to be possible to find someone who can sponsor a visa for you. If you choose to pursue a PhD in the UK, remember that student visas are not meant to lead to settlement, so once you finish your degree you will have to leave the country unless you can find sponsored work. If you're just looking to live here for a few years and are willing/able to take on the cost of a degree, then the PhD route might work for you, but if you're hoping to stay longer or work, you will have an uphill battle making that happen. The UK government is currently working on closing some routes for immigrants and making the ones they don't close harder, so it's definitely a challenge to immigrate here.
Do you have any other skills that could help you find a job? Any recent UK or European ancestry?