Infatuation has an element of sexual excitement. Whenever you are together, you hope it will end in intimacy. Love is not based on sex. It is the maturation of friendship, which makes sex so much sweeter. You must be friends before you can be lovers.
Infatuation lacks confidence.
When they're away, you wonder if they're cheating. Sometimes, you check. Love means trust. You are calm, secure and unthreatened. They feel your trust, and it makes them even more trustworthy.