What is the ruling on someone who is accustomed to masturbation and wishes to marry, but faces difficulty in completing the matter? And is the one who masturbates considered to be from the people of Lot?

Masturbation is not sodomy, but it is forbidden. Repentance erases what came before it. The questioner should not let his failure in proposing to some women cause him to despair of marriage. He should have a good opinion of his Lord and continue to search for a righteous wife. Repentance and supplication are among the causes of Allah's granting success and fulfilling what is sought.