I really can empathize. I had brain surgery and both where they took out the tumor and where they put in a drain (sorry if TMI) I don't have hair and my hair is thin to start.
Your situation, I'm sorry to say, actually sounds worse because it's in the part. Can you part it on the other side?
Or do a style without a part?
I hope it turns out that the surgery is minimal. Please post back! BTW, I have found that coloring my hair makes it thicker, so if that is an option for you, think about it. The permanent color coats the strands.
2/c and some 3A. Modified CG.
Highly porous. Color over grey.
Best 1st day method: Super Soaker
Conditioners: Curl Junkie Beauticurls Strengthening Conditioner,
Deep condish: Curl Junkie Curl Rehab
Stylers: Experimenting with cones & sulfates while the dews are high. Sometimes try roller sets - classic glamor but I prefer my curls.
Every day is a gift