Masturbation is classified under sexual sin. If you’re looking for a direct verse from the Bible specifically talking about pleasuring yourself, I can’t tell you that you’ll find one.
For example, Matthew 5:28 states: “But I tell you that anyone who looks at a woman lustfully has already committed adultery with her in his heart.” Masturbation typically requires a fantasy, porn, etc. That is a blatant sin.
God created sex so that we could give ourselves wholly to the one we are married to. So if you’re masturbating, you’re not giving, only receiving. Sex between a married couple is a gift given to one another, and if you’re doing it to yourself, it’s due to selfish nature, which is condemned in the Bible.
Those who belong to Christ have crucified the flesh with its passions and desires (Galatians 5:24). We’re called to keep our hearts and minds in check and free from sins of the flesh. Though it isn’t directly mentioned in Scripture, masturbation is still a sin. However, it is able to be overcome and able to be forgiven if repented of.
Praying for you!
and nothing can make them stumble."