There is a difference of opinion as to whether halachic prohibitions on deliberate sexual fantasizing apply to women. There may be room for more leniency in a case such as you describe, where the purpose is to help the married couple's sexual relationship.

However, "explicit erotic fiction" is a bit of a minefield and not in character with many Jewish values. So it would be best to limit this as much as possible and far preferable for you to explore other ways to become aroused. These other ways could involve your husband (making time for romantic gestures, or for non sexual touch such as massage). They could involve creative writing of your own fiction involving the two of you. They could involve even more simple measures such as taking a babysitter in the afternoon to get more rest, which can make a big difference in desire.

Please write back with any further questions.