Blinking lights problem

Hello,
I have a 98 Ford Explorer with about 160,000 miles. During the blizzard we got here in the north east this past weekend I put the car into 4W drive while I was driving around. Later I went to shut the 4W drive off but the light did not go out on the dashboard and the car still felt as if it were in 4W drive. I tried putting it in reverse to get it to turn off but it did no good. Then both the 4W drive HIGH and LOW lights started flashing at me every couple of minutes. The car also felt as if it was lurching slightly forward when i would slowly begin to accelerate after slowing down or stopping. So I stopped driving but just before I turned the car off the O/D OFF light started to blink as well. I've driven the car once since then but havent been using it in case I break it more. Can anyone tell me whats going on?? I'm at college so and my dad is down in Florida so he can't look at it. Help please! I don't know what the problem is or what to do!!
THANK YOU to everyone who responds!!

Fords and cold weather doesn't mix well, but did you follow the instructions on how to put the truck in and out of 4wd., just a thought,, or try to put it in a garage to warm up a little while.