Carnassial Abcess - Surgery Next Week!

I brought my 9-year-old Dachshund Susie to the vet today because she had a lump under her eye. I watched it because I thought it was a bug bite, and the swelling went down. I brought her to the vet because it swelled up again and turns out, it's a carnassial abcess.

The vet recommended that they remove the tooth. It's a big molar in back, so I was wondering if it would affect how she ate? I give her kibble (no wriggling squirrels or anything she'd actually need those teeth for) but would it be too weird for her to eat kibble without that tooth?

Also, it's a major dental surgery. She has to be put under. I'm waiting to hear back from the blood test first, and then I'm gonna bring her in. She's never been put under before. How do they react? Is she going to be excessively tired? (I've never had anesthesia either, so I really am clueless here)

I'm very nervous, as she has been completely healthy and has never needed any sort of surgery. Has anyone ever dealt with this before? Any information is greatly appreciated.