Lust is simply an overwhelming desire or thirst for something, but it is a selfish impulse, you want it because you want it. Or because it makes you feel good. It's usually based on physical attraction or what someone or something can do for you.
Love on the other hand is selfless, it's a desire to take care of someone else, to put their needs first, to do whatever is best for them, despite your own feelings and needs. Love isn't always a feeling, it's a choice, an act of the will. When you marry someone or even commit to them, you make a choice every day to love that person, to make them a priority, even when they make you angry.
Hope that helps.