I will agree with you that sometimes humor can be hurtful. Most of the humor used on this site is well thought out and if directed at another person it is generally written or sent or in the case of chat, typed to a person that enjoys the humor of the moment. But sometimes in chat, I know some sometimes get carried away in the heat of the moment and humor turns ugly. As for jokes written in books or seen on TV, or sent out in other various ways, no matter how much care or thought put into such jokes, there is aways going to be someone who is offended by what is said. This is just human nature, we are all different and things said or written affect us or cause triggers that hurt.
I hope being here on this site helps you in dealing with the hurtful things in your life and know that we are all struggling to deal with our emotions in one way or the other. But we also try very hard not to hurt anyone else, but try to instead be a new friend.