Hi, I Am Having A Problem. I Am Taking Effexor

Hi, I am having a problem. I am taking Effexor has been for several years. When I miss a dosage I get this zapping feeling in my head and as soon as I take my pill in a few hours I am feeling ok. Will this time I don't remember missing taking my meds, but for the last 3 days I fill as if I didn't taking my med. I don't know what is going on. I feel sick at my stomach and my head feels like I getting some kind of electric waves shooting thru it. I never felt like this before. Is it possible that something is going on with me, that my medicine is causing me to feel this way? What can cause me to feel so sick? I know what happens to me when I miss taking my med, what I am feeling now is the same way I feel when I miss. What do you think is going on? Should I talk to my doctor about try something different. I wanted to get off of the Effexor, I dream so badly and never seem to get a good night sleep, but when the doctor reduce my med to 37mg and told me to take one every other day I started to have the zapping feeling in my head and the feeling and a few other things start to happen.