How can one repent from walking without ritual purity, excessively masturbating, and mostly remaining in a state of ritual impurity?

A sincere penitent is not harmed by their past, for what truly matters is their state after repentance. If the conditions of sincere repentance are met—namely, regret, abstaining from the sin, resolving not to return to it, and uprightness—then Allah will transform their evil deeds into good ones. The magnitude of the sin does not matter if you repent and become upright, for Allah is All-Forgiving, All-Merciful, forgiving all sins. As for bad habits, they must be avoided. Regarding a state of ritual impurity (janabah), there is no harm in remaining in it and walking while in it, as long as it does not lead to missing prayers. It is recommended to turn to Allah and increase acts of obedience that erase evil deeds.