I was in a similar situation as you in January - I had a lumpectomy for “benign with atypica”, had never had a general anaesthetic, and became very anxious about it as I approached the day. My pre-op was on a Monday 2 days before, and my blood pressure went very high as it all became very real. You will have lots of questions to answer at the pre-op, and they will give you all the information about what to take with you (it may be different in different hospital/ operating suite set ups for day cases), and when you have to stop eating/ drinking. I recommend trying to focus on the practical things/ planning some nice/ easy meals for the few days after your op. If you haven’t got this already, I’d recommend getting some non-underwired sports bras, as this is recommended to provide compression to reduce swelling / help healing - surgeon advised to wear 24/7 for first 2-3 weeks). (I only had underwired and had to send daughter and hubby out to M&S to buy 2-pack after I got home from op!)
I rationalised my concern when I realised that doctors op1erate on patients in emergency situations/ far more risky operations.
My anaesthetist was great and reassuring/ explsined about giving anti anxiety meds given with the anaesthetic and it was her job to manage me during the operation. Last thing I remember before anaesthetic took effect was her telling me to think of a holiday/ warm sunshine and that I was doing a good job bringing BP down.
Although it’s good to plan to be waiting around, in my case I didn’t experience that - I was in BC unit for wire insertion at 8.30 and op due at 10.30 earliest, likely 12.00 but change of surgeon on the day meant they were ready for me at 9.10 so it all went very quickly - op took about an hour, and I was back home by about 2.30pm.
It was all a bit surreal on the day but the team of Nurses, Health Care Assistants and Anaesthetist and Surgeon were all impressivly professional and caring, and good at dealing with sensitivity and anxiety in a genuine and reassuring way.
It wasn’t painful (my biopsy was worse) - I didn’t need to use the stronger pain relief after first day - just had occasional/ sharp nerve sensation for a second or so for a few days, although the swelling lasts a while and you may have to adjust sleeping position to be comfortable.
Be prepared for tiredness in the recovery period - it was more than I expected but listen to your body and take it easy, but do work on the post op exercises too!
Your concrrns seem entirely normal but you’ll be in good hands. I hope some of my reflections help!
Wishing you all the best gor a good recovery.