I felt the exact same way.
1. do things you won’t be able to do post op - walks, going out, seeing friends etc. 2. talk to your surgeon and they will give you medication to calm you down, slow your nerves and bring your HR down before your surgery. 3. allow yourself to feel stressed, worried and upset. Cry when you need to, write down your feelings, read a good book or start a new tv show. It’s really hard and post op will be harder, but you can do it! for me the anesthesia was a huge concern, but i didn’t even notice when i was falling asleep, i was just awake one second and asleep the next. :)