Will the strength of my memory and concentration return to what they were, and will this habit be an impediment in my married life?

Masturbation is forbidden, and it entails worldly and otherworldly harms. The effect it has on prayer, concentration, and memory is the best evidence of its harm. You have done well by repenting from it, and you must resolve not to return to it in the future. As for informing your father of the details of what you did, that was a mistake; a general notification would have sufficed. We hope that the effects of this sin will be removed by repentance. Beware of surrendering to delusions and negative thoughts. Rather, have a good opinion of Allah and go forth in your life with confidence and reliance on Allah, and supplicate with the "dua of the distressed" and the "dua for well-being in this world and the hereafter."