Very sorry to hear that, although it so easily could have been much worse. Yeah, keeping a puppy from running and playing is not easy, and it makes you feel like a horrible person. One of our dogs had to have surgery on her hip when she was about 6 months old. We kept her in a pen in the house, and took her on leash every time she needed to go outside. It was a lot of work and very sad, but we all got through it. She is 10 years old now. That leg still "pops" with every step, but it doesn't seem to hurt her or slow her down any.
Best wishes for a full recovery for Marlee.