If the weather is cold, let it sit overnight and try again in the morning. A wounded animal will mostly stay in the same direction. You have a solid shot on the deer. Day light will help tremendously.
I shot a deer in New York with the same situation somewhat. It was a really good shot. Lots of blood. Pools of blood from where it bedded down. This trail of blood and puddles of blood went on for over a mile. Still didn't find the deer. We looked for a very long time. Zig Zags, circles, back track. It happens and it does suck, don't give up just yet though.