Dog keeps biting my legs when feeling playful, can’t be dissuaded

Hi all, we've had our pup (1F) for about four weeks now. She's incredibly sweet, but also very energetic and very chewy. She gets nippy during playtime too. For the past 3 or 4 days, whenever I walk somewhere in the house, she'll start biting at my pants and thighs, to the point where my legs are covered in bruises. She's wagging her tail and it doesn't seem angry, but when she's doing it she won't be distracted by her toys or even treats. Even a high value treat like people food only distracts her for a second. Our trainer thinks she might have doggie OCD (she'll play and obsess over toys until 11:30pm+, for hours and hours). But is there anything I can do while waiting on a vet appointment to talk about medicine? Standing still doesn't help, walking away makes it worse, trying to manually stop her makes her think I'm playing. I'm writing this from the bathroom right now because it's the only place I can find some calm!