im a 19 year old male i would like to know why im not shir about stuff like when someone asks me question and I know the answer but dont tell them i just tell them i dont know if I do tell them be telling my self could be wrong even esayest stuff i be like that or when i work cachier people give me money and i give them thier change back after they leave i tell my self did give them the right change or not I want to know why do I dought my self is it becuase i havent jackedoff two months half now i dont like to work cachier havent had sex need answer thank you and how to jackoff without getting an infection