To answer your first question: I tore my gracilis when coming off an with a leg twisted after becoming stuck in the pedal, and it took about 16 weeks to heal, the latter 4 of those were very very low intensity.
Its a major support muscle helping the knee twisting motion, but is quite a delicate one – I’d let it heal first, then when the pain has gone, try to ride very very gentle as an assessment and go from there.
If you are cardio fitter, its possible you are mentally applying more effort through your legs but actually putting more strain on your muscles, but in reality its probably the cramp that damaged it.
I’m not medically qualified btw, just going on my own experience.