Your clinic told you right, to take 1/2 of your normal dose tonight. I, however, would resume my usual dose tomorrow but do as the clinic says if you want to.
I also check my INR every week with my home monitor & so I'm able to be on top of it sooner if it's either too high or to low & then do the adjustments & check it again in about a week. I can also relate to you feeling cold when your INR is on the high end; that's kind of the way I feel too. Although, doctors & others say that one cannot feel any different one way or the other but I sure can, & I've been on coumadin for over 30+ years!
My dose was 10mg every day & 2 days of 7.5 like yours but now I've had to change it to 10mg for 6 days & 7.5 for one day in order to keep it within 3.0 - 3.5. I kind of prefer the lower 3's anyway! I would almost feel compelled to advise you to do this too if it weren't for the fact that you have to wait 1 month before you test! To me that's too long!
Hope you get back in range soon & if you haven't already, tell, don't ask your doctor, that you want to get a home monitor because it would certainly be so much easier for you & more reliable.
May/1975: AVR & MVR -- St. Luke's, Houston TX (Denton Cooley, Surgeon)
Dec/1975: MV Repair -- St. Luke's (Dr. Cooley)
Mar/2006: AVR -- St. Luke's, Houston TX (George Reul, Surgeon)
"Nothing in life is to be feared, it is only to be understood. Now is the time to understand more, so that we may fear less."
- Marie Curie