Do i have a brain tumor?

One of the nasty side effects of anxiety and panic disorder is the feeling of "impending doom", meaning that you think you are going to die any minute now, but have no specific reason to validate why you feel this way. If you've been taking the Paxil for 2 months now and it isn't helping, it is probably a good idea to switch to another medication or to increase the dosage. Talk to your doctor about it. You may also need to start taking an anti-anxiety drug, such as Xanax or Valium along with the Paxil. Please see your doctor as soon as you can. Meanwhile, look up signs and symptoms of Generalized Anxiety Disorder as well as the signs and symptoms of Panic Disorder. You will find that your symptoms will probably match one or both of these conditions better than "brain tumors".