What can I do about my inability to stop masturbating, given that I have a physical illness that prevents me from performing many prayers and achieving proper devotion in them, even though they are the two ways to quit?

Prayer prohibits indecency and evil, but it is not the only way to get rid of masturbation. The distraction you experience in your prayer is not an excuse for engaging in this habit, for prayer is accepted and its effect of prohibiting the servant from indecency and evil is achieved. No matter how much the servant is unable to fulfill some of the conditions, pillars, and obligations of prayer, this does not prevent him from benefiting from it.