Let's take love. You have garnished a certain amount of love within you that you personally are capable of. It could be really low, really high, or somewhere in the middle. Same goes for anyone else you may encounter. You cannot expect that person to give you love to make up for what you feel you lack. Love is not a commodity - a physical thing. That person may have massive amounts of love but while he can share it, he can never give it away. You can be satisfied,though, that the combination of your love and his love makes up a greater whole. Just do not expect anyone to give you love. You have to all ready have love you can share - and that means loving yourself first.
By the same token, you cannot "lose" love. You can feel like your love has gone. You can even chose not to love. Again love is not a thing - not a commodity. So when there is, say, a break up, there are feelings of loss, anguish, sadness, and even anger. You will eventually love again, though, if you choose to. Love is an emotion.
Well, let's put it this way. Anger. You get really, really angry - wreck the room, smash the windows, call someone bad things. Then it is over. Have you lost anger? No, you are capable of getting just as angry somewhere down the line - and perhaps even more so. Love is like this. You can express the hell out of it, and even feel like it's not in your life anymore, but eventually it peeks out again.
I feel sorry for those who state positively,"I'll never love again" or "he took all of my love". They are acknowledging a choice not to love. What is worse, they are accepting the false ideal that they are not worth loving.
Love is the most wonderful experience there is in the world. It is a shame that too many people give up far too soon. If you are still searching, it is only because the right person has not entered your life yet. When he does, you'll discover the wait was really worth it.