A 17 year old female gets short and very painful headaches along with dizziness. she walks weirdly at times and has tunnel vision in one eye. what could it be?

Hydrocephalus : Consider first seeing a neurologist as soon as possible. One possible reason is nph : normal pressure hydrocephalus which is a build up of excess fluid in the spinal column. This can be seen in young females who are obese (don't know your weight). Also multiple sclerosis needs to be excluded. Again go see a neurologist as soon as possible, don't wait.

See a doctor.: These are symptoms of something going on inside of the brain. See a doctor soon.

Brain tumor: This is most likely a brain tumor, increase intracraniqal pressure ( pseudotumor cerebri), or a severe form of migraine headaches. There can be less common cause like ms or blood vessel abnormality. This should be seen immediately by at least an ophthalmologist.