Hang in there. Three days is just the beginning of the tough few days/weeks. But it is NOT forever...coddle yourself, broth, crackers, sips, maybe some OTC meds for symptom relief (eg: something for nausea, for muscle aches,...). If you enjoy and have access to a bath with a scent that you find soothing, do that, ...whatever soothes, take time with it, and keep busy with relatively mindless tasks...repetition can be soothing (whether it's playing solitaire, knitting, rocking...). Get outside if you can for a little bit at a time...play like a kid...
That you slept well is good.