Anxiety over proccedure

Ok so I'm scheduled to have surgery and remove an extra bone from my ankle, causing me to miss work for at least a month due to no weight bearing. I told them last week I believe on Thursday that I would likely have surgery within the next 2 months. Then about 4 days after that I got a called and surgery was scheduled for the 20th of this month. I immediately informed work and I plan to get work excuse and potential return time frame from my surgeon. I've worked at this restaurant for 8 years, and I would hope they wouldnt do anything shitty but I cant help but shake the feeling something may happen. I sent a message to my general manager giving some details and he just said ok. And I know a normal person would probably not look too much into it but frankly that wasnt very reassuring to me. It just im worried about the procedure. But id like to do it while I have my medical card so I can actually not go into debt getting it, I have to reapply for eligibility im a few months. I guess im just trying to get an opinion, did I give them enough time, I said I can and will work the most recent schedule but would need the next month off and, idk im just nervous I guess