Sorry but you are making the classic mistake of someone on holiday who decides to buy a small property there. Being a flying instructor is miserably repetitive work that is dangerous and very poorly paid - McDonalds offers better money I promise you.
But you were on such a high during basic flying training that you import some of that joy to the job of the bloke sat next to you. Try it. It wears off real quick. You won't like it and more importantly the £6k the FI course will cost you will take 20 years to repay on an instructors wage.
You have little idea of how casually the industry will discard and ignore your paltry 190hrs of flying experience. I've done that in 6 weeks and the fact you spent £50k> means nothing kid.
There is a really big really hard world out there awaiting Wannabes who often resemble lambs to the big shed with the drip tray.
WWW