"Tension Headache" For The Past Two-Three Weeks?

I moved to California a few weeks ago, and I've been having what I could describe as a tension headache that comes and goes but persists throughout the majority of the day. It worsens whenever I do any strenuous activity, look at bright light, etc. But the weird thing is that sometimes when I sleep it makes it a LOT worse... for example, I just woke up from a five-hour long nap in which I kept waking up, fully aware that my head was pounding, but I just felt so exhausted that I went back to sleep after a couple of minutes. Now that I've finally pulled myself out of bed, my temples are pounding and the back of my head feels like it's got this uncomfortable pain/pressure. Is there any reason why I've been getting this and it's lasting so long?