Should a young man suffering from back pain get married, given his state of confusion?

You should present your case to a specialized doctor. If it is proven that the pain affects procreation, or prevents intercourse, or prevents you from working and earning a living, then you must inform the woman you intend to marry. If she accepts, then there is no blame upon you for marrying her. Otherwise, you would be deceiving her, and the Prophet, peace and blessings be upon him, said: "Whoever deceives is not from me." Scholars hold the view that any defect that defeats the purpose of marriage must be disclosed, and if concealed, it establishes the option of فسخ (annulment). Among the purposes of marriage are enjoyment, procreation, and service. Therefore, if something exists that prevents these, it is considered a defect.