My dog won't pee outside anymore! And he REALLY needs to go!?

My dog was recently in a big fight with stray dogs while we went away (my parents were home). Long story short, an $1100 vet bill later, he's confined to the house for the next couple of weeks, vet's orders. He's been an outdoor dog for about a year or so now (he'll be 2 next month), so we haven't had a dog inside for a while. The vet said he held his pee for 2 days while he was in the animal hospital, and for the 5 days he was there, he didn't poop until the last day. He was holding his pee when he got home for a while, even though we took him out - finally did it in the house. We scolded him, and he doesnt do it anymore unless he has no choice. Anyway, the past day or so, he hasn't peed or pooped when we take him out, and we take him out over 10 times a day. He can't stay outside alone because of the stitches/open sores, and there are flies/stray dogs around. He needs to pee so bad he's leaking small puddles when he sits down/gets up, and he whines to go out, but doesn't pee!!