You can make a life-long private vow of chastity to God. You can ask to be consecrated to Him and to consecrate your virginity if you are a virgin. God will let you know if He’s done it. If you ask Him to marry you and He says “yes” than you are mystically married to Him and He will let you know if He does say “yes,” (although I mean this in a spiritual sense, but He could potentially appear.) Such people are not encouraged to tell people about their private vows, but they can if they choose. They are still laypeople, but with real vows and or mystical consecrations and marriages so are not really “single” as single people can date and get married. Of course, if one makes a private vow of life-long chastity, and later changes their mind, they may ask a priest to dispense them from the vow. As for the other two things, I’m not so sure–at least not if the person was completely serious and sincere about what they were asking for and were mature enough to realize the seriousness of such things.
St. Catherine of Siena made a private life-long vow of chastity to God.
Then, there are consecrated lay communities with their own vows, which do not include a vow of chastity such as in a religious order, meaning you can be married and the vow of chastity is simply a vow to live as a chaste Catholic in your situation and your’re semi-consecrated–either as a single or married person. Of course, consecrated virgins too may join with no new consecration as they are already consecrated–at least that is how I understand it as why would they have another consecration?