its hard to rule out brain tumor when all you get is dizziness, lightheadedness, and headache. with brain tumor, the tumor expands affecting specific parts of your brain which is why physicians are looking for more than the symptoms mentioned above such as seizure, speech problems, loss of balance, tinnitus (constant ringing in ears) etc. Hot sweats are common to anxiety and does not imply brain tumor at all. you're prolly need some rest. the symptoms u mentioned are classic signs of anxiety. i wouldn't worry that much.