I have accidentally inhaled a lot of bleach and now my head hurts and I have a burning feeling in my nose. Should I be worries?

Possibly. If you mean you were cleaning with bleach and you breathed in some fumes, then you are probably ok. If your discomfort doesn't go away with some fresh air, you might want to get checked out however. If you mean you actually inhaled liquid bleach, then yes, you should be worried and you should see a doctor right away.