I think i may have bruise the bottom heel of my foot,it hurts when i walk/apply pressure,i'm a walker to school so it hurts more ,what should i do ?

Varies: First, I would have someone look at it just to make sure you don't have something stuck in there. If you bruised it like from an injury, stay off it as much as possible and should get quickly better. If you did not injure it, plantar fasciitis is most common cause; initial treatment for that is often NSAIDs and stretches. Be seen if it does not get better.

Hard to heal heels.: If you think that it is bruised because of a specific action that led you to that conclusion, that's good. Now you know exactly what is to be treated. If the bruise theory is pure guess and has no basis in fact, well, not so good. Heel pain always takes longer to resolve when use of the heel is not reduced or eliminated. This means no excessive walking or standing until it resolves. See your doc.