What should I do about my feelings of low intelligence and inability to study after my addiction to masturbation and my prayer against myself not to enter medicine if I return to it, as well as hearing my mother pray against me not to enter the Faculty of Medicine?

You must take the initiative to repent, frequently seek forgiveness, and adhere to the fear of Allah. For whoever fears Allah, He will provide him with a way out and a solution, and will provide for him from sources he could never imagine. It is wrong for a person to supplicate against himself if he commits a forbidden act, in order to stop himself from it. Rather, he must desist from it out of fear of Allah and ask Allah for success. It has been said that supplicating against oneself is null and void, with no accountability for it. As for a mother supplicating against her child, it is forbidden, and it might not have happened in the first place.