There can be some very simple causes of frontal (forehead) headache. Poor sleep, eye strain, refractive errors of the eye like myopia (near sightedness), temporal arteritis, compression of cervical spinal nerves (possible as you have dizziness too), and sinusitis are some of the common causes of frontal headache.
Since I cannot examine you and know other related conditions you may be having, nor is a detailed history possible on net, I have listed the various possibilities that should be looked into. Please consult your PCP for primary examination followed by proper referral. Take care!
The medical advice given should not be considered a substitute for medical care provided by a doctor who can examine you. The advice may not be completely correct for you as the doctor cannot examine you and does not know your complete medical history. Hence this reply to your post should only be considered as a guiding line and you must consult your doctor at the earliest for your medical problem.