Hi
I think you are doing far to much this early in your injury.
Your friends, if they are good friends will understand if you can ask for their help in getting the party started. Also you will need help with clearing up afterwards

Try to take breaks during the party, have a lie down for half an hour at intervals, this will help you get through it.
I have had PCS since June 2012, and finally managed to host Xmas day this year, but only with the help of all my family, I could not of done it other wise.
You are very strong person to want to do this but do not push yourself beyond your limit.

My husband has trouble still with my fatigue, although it is all but gone now, I still am careful not to over do things and I listen to my body all the time.
I hope your party goes well and just relax and enjoy the new year .
You must put yourself first for now.
I wish you a happy new year and healing.
Carole x