Will I go to hell for repeated masturbation and lust?
I have a great obsession for yiff. I seem to especially like the cub art. If you don't know, Yiff is a fictional depiction of anthropological mammals, especially depicting their sexual intercourse. I am aware that bestiality and lust are sins. I keep masturbating to it, even after the realization of it being a sin. I am worried about being spiritually killed, but even more worried about straying away from God. I am especially addicted to females' navels. They perplex me and, for some reason, appeal to me. I just want to do sexual acts with them. I don't usually look at human porn because it's morally wrong. Also, it doesn't appeal to me. I personally prefer yiff since it is drawn and not in real life. I am still worried. Is my lust for yiff and navels, plus my repetitive masturbation, going to send me to hell?
"For this is the will of God, your sanctification: that you should abstain from sexual immorality; that each of you should know how to possess his own vessel in sanctification and honor, not in passion of lust, like the Gentiles who do not know God" (I Thessalonians 4:3-5).
What you appear to do is substitute one form of pornography for another. You tell yourself that drawings of sex is not as bad a films of sex, that depictions of animals or people with animal features is not as bad as depictions of humans, but the end result is the same -- it is still pornography. It is still a depiction of lustful things created to stir passion in the viewer. Therefore, it is still sinful.
One some level you know this is wrong. That is why you worry about it.
Masturbation, by itself, is neither right nor wrong. It is similar to asking if sex is wrong. Sex between a husband and wife is proper and expected (Hebrews 13:4). But sex between two people who are not married to each other is wrong. In a similar way, masturbation by itself is just ejaculating excess sement, but using pornography to arouse yourself so you can masturbate is wrong. See: Is masturbation sinful or not?
The problem you are having is with lust. You are wanting to have sex with someone you are not married to. "For from within, out of the heart of men, proceed evil thoughts, adulteries, fornications, murders, thefts, covetousness, wickedness, deceit, lewdness, an evil eye, blasphemy, pride, foolishness. All these evil things come from within and defile a man" (Mark 7:21-23). Lust involves justifying sin in your mind, but that line of reasoning makes it more likely that you'll sin when the opportunity arises.
Rather than search to sin in what appears to be an acceptable manner, a Christian should be looking to get as far from sin as possible. As a male, you have to ejaculate, but you certainly don't need porn in your life.
Thanks Jeffrey. God bless you.