that is a heartwrenching poem. the poet has been badly hurt. I cannot tell whether it was by a lover or a parent. I know I have felt this way about either at times. it sounds more like a parent because of the boy you built line but I don't want to presume. I think a lover is a part of building oneself as well. They are often a big part of how you measure yourself against the world. If that yardstick is ripped away it can tear a person down and lead to some of the feelings expressed in this poem.