British Expats - Temporary move to Spain/Canaries. Please advise.

Hi everyone,
I am really hoping that someone could provide me with some advice please.

I am a British citizen with a EU passport.

I have lived in the UK all my life. I am single.

I have suffered chronic illness this year and I am thinking of relocating to Spain on a temporary basis to recuperate (maybe 3-6 months?)

Unfortunately I don't have the income to relocate to Spain permanently and I am extremely unlikely to get a mortgage (plus I am not brave enough and I have responsibilities in the UK!)

The reason for the decision is to have an extended holiday, relax and recuperate, so I will not be lookkng to work in Spain, or to live there permanently.

I want to keep costs as low as possible as I will be using some of my savings to facilitate this. So ideally less than £500pm.

...a studio or small apartment would be ideal.

What is the cheapest and easiest way to go about this? I could do an extended holiday rental, but it's working out extremely expensive....plus how would I manage money (access to) utilities costs, healthcare and comminications whilst away?

Would a special, extended holiday insurance policy provide cover if i fell ill or had an accident?

Would I require any permits or anything and if I took out a 6 month let on a small, private apartment, what would be the terms etc?

Could i leave before the end of the 6 months tenancy if I needed to return to the UK?

I am learning Spanish and whilst I can manage the odd sentence; i am a long way from fluent so I would ideally want to be in a coastal area or an area with a good amount of tourists or expats.

Last but certainly not least, I am pretty unfamiliar with mainland Spain, I have been a few times to the tourist resorts on holiday, but I have not explored further.

I love the Canaries particularly Lanzarote, I have been to the island several times and I am very familiar with it.

Ideally my first choice would be Lanzarote.... but if it's not affordable or possible; do the same rules apply there as mainland Spain and other areas?

I am unsure as to what to do and what area or part of Spain to choose.

Any help or advice would be so appreciated.

Thank you