Weak legs

Ok im probably overreacting after seeing the extensive use needed to get to this point but i did a (i think 300g) can of nos on the weekend and im really scared of the fact u can lose ur legs from it however have only had a few symptoms once, for context i only do nos (one can) probably every 6 months so i think im in the clear however my left leg has started feeling really weak and its been 2-3 days, ive been taking two b12 tablets a day but im worried imma be paralyzed, can someone calm my nerves or something please