Just bear in mind that not everything affects you and if it does, ask yourself: "How long will this actually last?" You're a human being. The reason our species has become so "dominant" is our ability to adapt. When they say "survival of the fittest", they don't mean the morbidly obese get left behind. It simply refers to the extent to which you can adapt to challenging situations in which you are placed.
So just remind yourself that in order to survive this world, you have to learn to adapt and take things lightly. If someone hurts you, just walk away or be sugar-sweet with them and watch them burn on the inside. Guilty feelings arise when you blame yourself, but why should you be to blame for so many trivial things? Sometimes things just happen. It's how you deal with them that matters.
So, whenever you are faced with a situation which you feel might harm you, take a deep breath, remember that whatever happens you can overcome it because it is in your basic nature to, that not everything is your fault, and that pain only lasts as long as you allow it to.