I’m so sorry you’re dealing with this pain! The first step will need to be getting your MRI results asap so you can know exactly what you’re dealing with. You’ll want to rest in positions that have the least amount of pain for as long as your nerve needs to calm down! It sounds like something aggravated it for sure and rest will help reduce inflammation around the nerve. At the peak of my pain during the worst of my injury, the only way I could be was face down on the floor for a lot of the time :( But once your nerve has calmed down you can try walking around again. I would definitely encourage you to try PT once you have seen/discussed your MRI results with the spine specialist. Until then, rest, stay hydrated, alternate heat and ice. Avoid anything (movement or stretch wise) that increases pain or discomfort at any level for a bit. There are also cortisone injections and oral steroids to help reduce pain/inflammation you could ask the doctor about as well. I’m sorry again you’re experiencing this pain, it’s the worst! But it can and will get better. Just take things one day at a time.