strange sensation of motion, like when in an airplane?

For the past 3 weeks I have experienced a strange sensation of motion, like what it feels like when sitting in an airplane. I feel like I am moving up and down slightly and this is usually associated with slight pain and pressure that is always on the right side of my head but seems to migrate from above my right eye to the base of my skull; sometimes it is the entire right side of my head. Hopefully it is not an aneurysm or a tumor. I do not notice anything odd with my ears (ringing/pain) and I am not experiencing nausea. I have not been to a doctor yet but am strongly considering it if this continues for much longer. Thanks in advance for any advice.