All perfect praise be to Allah, The Lord of the Worlds. I testify that there is none worthy of worship except Allah, and that Muhammad is His slave and Messenger.
It is not permissible for you to buy artificial breasts to touch and enjoy them because this is a door of temptation and a reason for falling into immorality. Islam came to block every means that leads to what is forbidden. Allah Says (what means): {And do not approach unlawful sexual intercourse. Indeed, it is ever an immorality and is evil as a way.} [Quran 17:32] As-Si'di said about the interpretation of this verse:
"The prohibition of approaching (getting near) it is more emphatic than the prohibition of doing it because the prohibition of approaching it includes the prohibition of all what leads to it and its prohibiting what causes it: 'The one who goes around what is prohibited is most likely to fall into it', especially this matter because the desire for it is strong in the hearts of many people." [End of quote]
Abu Hurayrah narrated that the Prophet said: "The child of Aadam will have his share of Zina (adultery or fornication) no matter how well he/she endeavors to avoid it. The Zina of the eyes is by gazing; the Zina of the ears is by listening; the Zina of the tongue is by talking; the Zina of the hands is by touching; the Zina of the foot is by walking [to what is forbidden]; and the heart desires and wishes. Then, the private parts either submit to this or refuse (to submit)." [Al-Bukhari and Muslim]
Therefore, look for a way to get married, first by relying on the Help of Allah and then the help of trustworthy Muslim brothers. If this is facilitated, then all the best, otherwise you should keep yourself chaste by (frequently) fasting and other means that help you maintain your chastity, until Allah makes it easy for you. Allah Says (what means): {But let them who find not [the means for] marriage abstain [from sexual relations] until Allah enriches them from His bounty.} [Quran 24:33]
Allah knows best.