There could be any number of reasons why your prayer was not answered in the manner for which you hoped, starting with the fact that it appears that you said it in a superstitious manner. Here is what the Catechism of the Catholic Church has to say about superstition (note my emphasis):
Superstition is the deviation of religious feeling and of the practices this feeling imposes. It can even affect the worship we offer the true God, e.g., when one attributes an importance in some way magical to certain practices otherwise lawful or necessary. To attribute the efficacy of prayers or of sacramental signs to their mere external performance, apart from the interior dispositions that they demand, is to fall into superstition (CCC 2111, emphasis added).
The wording of the Memorare is not intended to oblige the Blessed Mother or God to answer your prayer in exactly the manner in which you specify. It is a statement of utter trust, said with the knowledge and 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, even though you may not have recognized her assistance. Perhaps she obtained for you the grace to carry your burden with courage and patience. Perhaps she even obtained for you the grace to delve more deeply into your Catholic faith and find out how to pray in a more devoted manner (which is what you did in fact do). By all means, keep praying the Memorare for your specific intention. But please pray it while keeping in mind Jesus’ own 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).