Love certainly exists. Romantic love, familial love, and even platonic love are very real. They're unique things and they can stir up specific feelings and broad feelings. Love itself is very hard if not impossible to describe but the feelings are easy. The feelings are easy to see and those can be easily traced to love, but love itself is hard to see.
Love is ultimately your commitment. Love is the existence of a mutually beneficial relationship. Yes, there's selfish elements on both ends, but it's the mutual concern for each other's selfish elements that can keep it going. Love stops being so lovely when people lose their stakes in either themselves, their lovers, or both. Lose the foremost and it becomes obsession or dependency. Lose the medial and it becomes manipulation or abuse. Lose the final and it's depression or disassociation. Love hurts more than anything to lose because it's so amazing to have. Don't live in the shadow of love lost, though, as strong as its pain is. Let those who hurt you live in the shadow of your love, and the ones you hurt see your compassion.
That's how I've gotten out of the ruts of the many loves I've lost and the many that have been trampled.