Is it possible to return to the practice of masturbation, and does it affect the blood that comes out upon marriage?

Your stopping masturbation is a good deed, because it is forbidden and leads to religious and worldly harms. Do not preoccupy yourself with thinking about its consequences after marriage. Rather, occupy your time with what benefits you in your life and your hereafter. Be keen to associate with righteous women, and beware of loneliness which might lead you to do it.