The question is a bit vague. Come here on 60 day tv and extend for 30 days. Travel around. Find somewhere you like and rent a place. Next step long term visa which has many possibilities according to your situation. Best thing to do though is to get out of the UK before it's too late. Go anywhere.
You need a tm30 registered at the place where you are going to need to go to the local immigration office for something. Dont forget that when you stay in a hotel your tm30 is registered there so you have to re do it when you get back to your normal place of residence. That is what my office expects anyway.
You are entitled to bring 3 months supply of any drugs you are prescribed from the UK. That should give you plenty of time to find what you need in Thailand either from a hospital or pharmacy. The hospitals are often cheaper.