Lovey, I'm keeping my fingers crossed that the moment on the stairs is a harbinger of wonderful things to come with the Remimiracle.
The coldness you felt seems to be de rigeur. I often feel it, as do several others at the clinic I go to. The exhaustion afterward could be a combination of the stress you've been under and the infusion. However, I often feel off for a couple of days post infusion and the day of, I'm toast.
Welcome to the world of anti-TNFs, sweetie!
Many hugs,