The best way I have found to "toughen" myself up is to accept myself. So you cry when you are hurt/upset? Start from there with acceptance and comfort yourself rather than trying so hard to change and criticize yourself? Yourself may be trying to get your attention and when it does, it will know you are there and it does not have to feel so hurt and alone. It is always easier for me to take criticism or another person's ugly words if I have a friend with me. Be your own friend and mean-spirited people making fun of you won't bother you as badly.