The wording of the Memorare is not intended to oblige the Blessed Mother or God to answer your prayer in the exact manner that you specify. It is a statement of utter trust, said with faith that the Blessed Mother and God will always answer the prayers of the faithful, even if the answer given is not the one for which the supplicant hoped.
It is possible that the Blessed Mother did help you in your particular trial. Perhaps she obtained for you the grace to carry your burden with courage and patience. Perhaps she obtained for you the grace to delve more deeply into your Catholic faith through prayer, which is what you did in fact do. By all means, keep praying the Memorare for your intention, keeping in mind Jesus’ example of prayerful supplication for the relief of trials: "Father, if thou art willing, remove this cup from me; nevertheless not my will, but thine, be done" (Luke 22:42).