Losing oxygen to my legs

Bu
So I bought a size 1 diva cup and have tried it twice now. Both times my knees and toes started getting tingly, which I'm pretty sure is a sign they're slowly falling asleep. 
Do y'all know what cup might be better for me? I'm a 4'9", 21 year old that weighs 95 lbs and has zero kids. 
I'm thinking a Femmycycle Petite but I don't want to go wasting more money. 
Is there a recomendation chart rather than a cup size chart I could see? Do any of y'all have the same measurements as me and could recommend?
Also, what do I do with a barely used (and I mean less than 20 minutes of use) menstrual cup?