What Causes Pain In Head Along With Dizziness And Nausea?

For the pst couple of weeks I have had a strange pain at the top of my head, coupled with a feeling of dizziness and occasional nausea. when I touch the top of my head it feels tender, as if I might of had a sunburn, but id have not. Although I sometimes get headaches I haven t had one like this before and it does not respond to pain killers either. i did wonder about sinus or ear infection but in the back of my mind is the worry of a brain tumr or cancer. I have seen my doctor but she says if I had vertigo-ear infection in the past this might be all it is. However, I am concerned so please advise, Thank you.