Hi,
Are you taking any treatment for sinusitis? Clogged sinuses can cause pressure headaches.
Lightheadedness, nausea and tremors indicate a migraine attack.
If your migraine attacks are not being controlled by Imitrex you may need to be put on an alternate anti migraine drug.
Please maintain a headache diary to keep a log of your headaches as this way you will be able to identify a trigger for your headaches.
Take care!
I have experienced these type of symptoms also.Which is why I'm about to tell you this story...I have this pressure Mainly on my left side and had numbness and tingling along w/ it. I acutally had some blurry vision and got really confused and thought I was dying. . Originally I went to the ER thinking it was a stroke or an anuerism they did a CTscan and found nothing. Well the feelings are still here a month later. I have since had an MRI of the brain (neurologist MS ruled out), Blood tests, Heart & Corotid artery ultrasounds. They found nothing. Today I had an appointment w/ a Chiropractor that almost immediately found that I may have a bulging disc in my neck! This makes sense because the discs can force pressure on the nerves in your spine and cause many different odd feelings in your body including numbness and tingling etc. I highly recommend that you see a Chiro about your neck to start. I wouldn't stress about it, but I advise that you definately talk to a Dr. about what your going thru.
PS. I have also had the shaking, mainly in my upper body and hands mostly. I think mine could be that I started Zoloft about 3 weeks ago and the shakiness started about that same time frame.