If you get hypothermia once does that mean you’re going to be cold for the rest of your life?

I wouldn't think so! Hypothermia is only the condition during the cold experience when your body cannot produce heat as fast as it is being cooled down. However, it could be neurological (you are thinking about being cold, therefore you notice it more), or it could actually be peripheral nerve damage, (sensory nerves) depending on how severe the hypothermia was when they found you and warmed you up, or if extremely severe (you nearly died), then it could be gray/white matter damage in your brain that is incorrectly processing your sensations.
I think the most likely thing is that you're just paranoid though (actually not a bad thing, it's a great survival instinct, and are noticing your coldness more?) Either that or your body is still recovering? Not sure. Ask your doctor, not online! :)
Hope this helps!
-Mischief Goddess