Hi. I know that lust is a sin
Some of these questions would have different answers for a born again Christian and for an unsaved person.
But yes, lust = coveting is a sin. It is a sin to yearn for something that the Lord does not want one to have, a sin to have such a strong desire.
Having an itch to have sex is not a sin at all. That is the result of having hormones. Desiring sex is not lust and is not sinful nor demonic. What makes you think that your sex drive is too high? Why don't you see it as a blessing? However, if one does not use this with a husband then it becomes dangerous. Desiring to have sex with someone with whom one is not married is sinful lust.
Gal 5 says that the flesh lusts vs the Spirit. Gal 5 is about born again Christians only.
So this flesh which the Christian still has, this human nature (which is all the unsaved has)
exerts its opinions all the time or very frequently. In the Christian the flesh is like an alter ego, a Mr Hyde to the Dr. Jekyl. The flesh lusts (fact); it cannot be stopped from lusting. However, the Christian does not have to go into flesh mode (I am carnal, Rom 7) and make the lust of the Old Man flesh his lust. This is a temptation; and temptation is not sin.
So thinking one can make the flesh shut up & stop tempting us is wishful thinking; it will not happen in this life.
If you are thinking about sex a lot that is no sin. But it does suggest that you ought to get married (1 Cor 7 starts out ordering every woman to have her own husband because of the danger of fornication). It is better to marry than to burn with a sexual desire than has not satisfaction.
The Bible says nothing about masturbation. Masturbation is not a sin; lust for someone you are not married to is a sin.
The manic side of bipolar is sometimes expressed by sexual promiscuity.
Bottom line:
Thou shalt call His name Jesus, for He shall save His people from their sins.
To be a "His people" requires that one trust the Lord Jesus as SAvior.
Believe on the Lord Jesus Christ, and you shall be saved.
"I give them eternal life, and they shall never perish."
This trusting in Christ does not mean that He is just a chance-giver, but your Savior.
To become a child of God and have eternal life is free from trusting Christ as Savior.
Some express their faith by calling on the name of the Lord for salvation.
For whosoever shall call on the name of the Lord shall be saved.
The Lord Jesus is the 2nd Person of the Trinity, God become man, who died to pay for our sins on the cross and who rose from the dead.
If you have not done so, why not call out now:
"Lord Jesus, please save me, change me, give me your free gift of eternal life, and forgive all my sins. I do now trust you as my Savior, and I depend on your atonement on the cross to pay for all my sins."
Come to me all ye who labor and are heavy laden, . . . and I will give you rest.
I include the above because I have no way of knowing if you are saved or not.
Once we are saved, "the just shall live by faith." We need to trust the Lord as Savior and depend on Him for wisdom in every spiritual situation.
Gal 2 tells us,
I have been crucified with Christ, and it is no longer I who live, but Christs lives in me; and the life which I live in the flesh I live in faith, the faith which is in the Son of God Who loved me and gave Himself for me. I do not make void the grace of God; for if righteousness is by the law, then Christ died for nothing.