I've been having a lot of headaches recently along with dizziness/vertigo. they don't necessarily happen at the same time. what could it be?

Probably migraine: Migraines are the most common cause of frequent headaches, and they are often associated with dizziness. Your otc pain meds are likely contributing to rebound/medication overuse headache, which causes the headaches to actually worsen in the long run. You should see a neurologist who can get you on a good preventative agent as well as a good acute agent (i.e. Triptan i.e. Imitrex) for the pain.