I am sorry to hear this, Pax! I know how much you were looking forward to your new life in Florida. BUT, health is #1, and then all the cultural things you've mentioned before are quite important too. Some places just aren't the right fit, and sometimes, it doesn't take all that long to figure that out.
We've been through this several times ourselves: our move to Belize, which we thought would last "forever" -- it soon became apparent that it was not the right fit for us, and we had some health issues as well (not as serious as yours, tho). Mexico, more recently -- we went into that with our eyes wide open after Belize, did not expect it to last forever, and when it started to become un-fun, we knew the time was right to move back to the US. We still love Mexico, and I wouldn't be surprised if we didn't try it again (but a different area) one day, but not right away. And long before either of these expat experiences, we briefly moved to Wisconsin and to Florida during our 31-year marriage. In both cases, my DH decided he was not happy (though I actually was, especially with our situation in Florida, because I loved my job), and we moved back to NC. And in those cases, that worked out well for us with work and everything else (friends, family, etc.)
In every case, we try to look at these experiences as things we learned from. They just added to the pool of life experiences and hopefully helped us to choose better the next time (though we are very slow learners, it appears!) In our case, I think we learned that we need variety, and that is why we are currently nomadic. We get bored and itchy staying in one place for too long. I suspect eventually we'll settle down, but we're in no hurry. I think your Florida experience taught you a lot as well; and I can certainly, completely relate to the desire to get away from winter -- that was one of the main drivers for us in both Belize and Mexico, and why we spent most of this past winter in Florida.
I wish you only the best -- in health and in life! Keep us posted!
Emily
2011 Jamis Dakar XC "Toto" - Selle Italia Ldy Gel Flow
2007 Trek Pilot 5.0 WSD "Gloria" - Selle Italia Diva Gel Flow
2004 Bike Friday Petite Pocket Crusoe - Selle Italia Diva Gel Flow