I hit the left side of my temple pretty hard on the corner of a shelf. it really hurt at the time but didn't lose consciousness or vision. felt fine but now a few hours later that side of my head is hurting and sensitive to touch. should i be worried?

Some pain is expected after your injury. It should start to diminish after 24 hours and slowly go away in 3-4 days. There is a remote chance that a hard hit can cause bleeding internally but that will cause more severe generalized headache and make you nauseated or vomit. These symptoms require medical evaluation especially if there is progressive increase; in that case see your doctor or visit ER

No you shuld be OK. The area that is sensative should be OK. A skull series z-ray may ne helpful if your PCP feels that it necessary.

Based upon your description, appears you have likely sustained a mild closed head injury with a resultant scalp bruise. Consult a doctor if worsening headaches, dizziness or imbalance, nausea or vomiting, visual blurring or double images.