Hi there Nicki: Like I said, I've had a 'desk job' for the past 12 years, but I was a staff nurse for 17 years. You know what the pace usually is on your floor, so for starters you're going to have to gage that energy level with how you're feeling. As of this moment, you aren't ready to go back yet. You still need to build your energy, both physically & mentally/emotionally (especially dealing also with facial/eye issues).
Getting back to work WILL be exhausting at first, there's no way around it. Definitely start back part time, see about 8 hour shifts at first, if possible, 2-3 times a week & see how you do for the first 2-3 weeks.
You may want to look into an area of nursing less fast paced, like education, human resources, infection control, risk management, etc.
I wish you all the best, Always good thoughts, Nancy