Melissa, I've had my tonsils out (as an adult) and so has my husband. I can tell you, from personal experience, that this is the kind of thing where you HAVE to go off the diet. Just like if you had to have an IV in the hospital, they'd give it to you, even if you were insulin resistant. I totally applaud your view that "this isn't a diet" and feel the same way, but there are times when, for your health, you have to go off plan. So here's what I'd suggest:
1. Try to stick to foods that are less likely to make your blood sugar spike (i.e. meat broth instead of fruit juice) if you can, but be prepared that you may be unable to do so.
2. Remember that sugar "coats" your throat and you may find that you really need it if the pain gets bad.
3. When I had my tonsils out, the pain was bad enough that I didn't want to drink or eat. Because I resisted so much (and DH was too sweet to force me), I almost ended up back in the hospital due to dehydration. My lack of drinking also just made it hurt more. So don't refrain from eating/drinking just because it's not on plan.
4. Don't expect to eat solids for at least a week, and more like 2 weeks, if you're like the rest of us. Plan to go back on Phase 1 when you are WELL and not before.
5. Stock the pantry with foods that are SBD-safe but also allowed under your doctor's orders. Things like unsweetened applesauce, cottage cheese, etc could work.
Be gentle with yourself. Yes, this is going to hurt and it'll hurt a lot. So take your pain meds. But know that it doesn't last forever. Sleep, follow your doctor's orders, avoid things with too much acid (i.e. sherbet!), and don't stress about SBD until you've healed. Trust me, even if you eat sugar every day, you are still going to lose a lot of weight while healing. It's just not possible to eat much because of the pain.
Take it easy and get a good nurse!