It's important to differentiate between infatuation and love, as you pointed out.
The feeling of infatuation is a subconscious projection of our full image of an ideal partner on a person who gives us the impression that he/she has some of the ideal characteristics. Thus, it is an illusion that infatuation is our relationship towards another person; infatuation is really a relationship between our own ego and our image of an ideal partner.
On the other hand, love is not just a feeling, it is a relationship of closeness based on repeating feelings towards a real, unique, complete person. Telling someone "I love you" is like saying "you are a wonderful, precious human being to me". Therefore, if we feel loved, we feel that someone recognizes and confirms our value as a complete being.
If we are not happy with "just" being loved and idealistically expect infatuation for the rest of our life, we will have a serious problem maintaining long-term relationships.