I feel like my doctor takes nothing I say serious, due to the fact that I have a history of hypochondriasis. Should I switch doctors?

Anxiety. I understand your frustration. Thank you for informing about Sexually Transmitted Diseases and Acid reflux Commend yourself in your achievements in education, work, relationships and hobbies. Do not think about symptoms a lot. Focus on satisfaction in your daily activities. Discuss with your Physician about stresses in your life, to develop coping skills; and your need to have empathy from him.
More info needed. There's not enough information to know whether your doctor is managing you appropriately or not. If s/he has blown you off after only 1-2 visits, without discussion or explanation, maybe change. But if you have repeatedly raised the same concerns or symptoms, maybe appropriate to not react. At a minimum, raise this question direclty with your docotr before making a decision. Good luck!