I totally understand what you are going thru. Maggie May was just under 3 lbs when she got spayed and I was a nervous wreck. She fine. She was out of it for about 2 days and then she was fine. She was in a little bit of pain the first night so talk with your vet about pain meds, dosage and when you can give her additional dosage if she should be in pain.
We'll be sending you hugs and good thoughts and prayers.
If you are considering having use an e-collar, click on the link in my signature...this might make her a bit more comfortable in her recovery.