Thank you for your question. Attractions come in all shapes and sizes and ages. Simply because you are attracted to older women does not mean that you have a problem. It is only a problem if it is impeding your ability to connect with women and to create a meaningful relationship, if that is what you want. While society seems to dictate that the man must be older than the woman, or at least the same age, that is not where our attractions always lie. We can spend a long time discussing and analyzing why people are attracted to particular types of persons, but the most important thing is to feel comfortable with yourself and with your attractions and to find someone who shares their attraction to you.
If you felt relaxed with the older woman and you feel sexually more comfortable with older women in general, than I encourage you to search out a sexual and/or emotional partner in an older woman. If you are comfortable with one another, that is an important step to fostering a relationship.
As well, there is nothing abnormal about your fantasy. However, it is important to recognize that sometimes fantasies are better left in the realm of fantasy, in order to maintain their appeal, while others are meant to be acted upon. This is something you will have to decide for yourself or in discussion with a (potential) partner.
As well, it is possible that you are looking for an older woman because they make you feel comfortable, secured and taken care of. This is acceptable as long as these dependency needs do not impact negatively on you or your partner. If you find they do, however, it may be time to explore –with a therapist, for example- why you have such dependency needs and how you could fulfill them in other ways.
Best of luck to you.
-Lorin, for Alterheros