Regarding feeling cold: Have you discussed your fasting with the doctor who prescribed you metformin? I wonder if the effect of drugs and fasting are a bit much together, and maybe the dosis needs to be reconsidered.
I am cold nearly all the time, when I’m indoors. I started my IF journey at 424 lbs., and as of this morning I’m 218 lbs, so I have a bit less insulation than before. My wife and I also like a nice, cold house – we keep the AC set to around 68.
My solution has been a Bearaby weighted blanked and a lot of around-the-house sweaters.