Well, I'd crack open a can of Toughen Up and swig it down. You are going to need mental fortitude to gut this one out alone. Tend to your injury first and foremost. Hopefully you have had some wilderness medicine training. Pull out the first-aid kit and tend to your injury.
Stabilize and treat your leg, and then focus on your other survival priorities such as signaling for help. That's where the PLB (Personal Location Beacon), signal mirror, and whistle all come into play. Again, survival is all about being prepared with a quality first-aid and survival kit that will help you get through such an ordeal.
If your friends don't locate you, then you may be in for a long night. In such cold weather and with a serious injury, hypothermia is going to be your greatest threat. Build a fire and some kind of shelter to cut the wind and snow. I always carry three firestarters with me at all times, as Fire=Life in winter. Melt some snow by placing snowballs on sticks around your fire and catching the runoff on a bandanna or depression in your pack.
Hunker down, stay hydrated and warm, and reflect on what is most important in your life that is worth fighting to stay alive for. Your will to live must rise to the forefront.
Pilot Peter DeLeo, whose plane crashed in the Sierras, hobbled out of the snow-covered mountains over 13 days with a shattered ankle and shoulder and broken ribs. His book exemplifies what the human spirit is capable of enduring under extreme conditions. Yes, you will have a grueling night ahead for sure but just remember that many survivors, with trauma far worse than yours, have made it. Know that you will too!!
I highly recommend to anyone spending time in the outdoors, recreationally or professionally, to attend, at the minimum, a Wilderness First-Aid course with a reputable company like the Wilderness Medicine Institute. They can show you how to deal with such injuries in the wild, when support may be hours or days away. You will be grateful for such skills when the time comes.