Do you need a permit to live in Mexico?

No – no permit required.  When you drive or fly in, as a tourist, you are allowed to stay up to  6 months –you fill out papers on the plane to secure that visa and you will fill out similar papers if you drive in – that is an FMT.  If you decide to stay longer, you have to leave Mexico, and then re-enter Mexico to secure another visa permitting another stay.  It may be wise, in that case, to secure an FM3, (180 days to one year)  and maybe even eventually an FM2.  The FM3 is what we call a perpetual visitor.  That allows you to stay a year - then that can be renewed another year, for a 5-year period.  Then, you can reapply – again.  That’s what retirees usually secure.  The process may take a day – possibly even two, so, be prepared, and be patient – at least when applying the first time.

By the way – do something for yourself right now

Place a bottle of aspirin beside your bed table now.  WHY?  If you have chest pain that is sever enough to waken you, all you need to do is immediately chew two aspirins and then swallow them with a bit of water.  It could save your life.  Then, immediately get medical attention – call 911. And while you are waiting on the emergency people to come, DO NOT LIE DOWN.  Sit on a chair or sofa near the front door and wait for their arrival