Thank you for your query. Would you please clarify a few things for me? 1) have you been diagnosed with Obsessive compulsive disorder? If so , by whom? 2) Why do you think you have a brain tumour, is it due to pains that you mentioned? 3) Do you unconsciously grind your teeth? When a person is anxious or nervous or emotional, teeth grinding (Bruxism) may occur which can cause the pains you mentioned. Try to make a conscious effort to recognise this behaviour and relax your jaw and facial muscles ( imagine holding some water in your mouth and maitain you really jaw in that manner). sometimes this happens during sleep and you may able to recognise it if you have pinched lines on the inner surface of your cheek on both sides. your molar teeth may also be worn out. The other symptom you mentioned ( replacing words, or not being to get the right word) is less likely due to a Tumor than a chemical or circulatory ( blood flow)disturbance. extreme anxiety can trigger your symptoms as well. I would suggest that you see your physician and discuss your problems freely. they will able to examine you and reassure you in the meantime, try to write down whatever thoughts come into your mind. it may help to clear things up and also give you something else to focus on during the thinking process. Hope this helps wish you good health