Questioning FND Diagnosis: Seeking Second Opinion

Am I crazy to doubt the diagnosis of FND and to want a second opinion? I know that having another neurological problem is a major factor in developing the neuropsych issue that is FND my neurologist refused to do further testing (including the testing I was sent for) which has me questioning elements of the diagnosis. However I'm afraid that questioning the diagnosis will negatively impact my ability to receive care in the future because I may be seen as crazy, a hypochondriac, or an otherwise untrustworthy paitent. More information if you want it: •I would likely feel better about the diagnosis if I wasn't in a situation where there are copious amounts of objective evidence that I have both an unspecified autoimmune disease, an unspecified blood disorder, and an unspecified cause of repetitive episode of hypovolemia with we're calling "chronic hypovolemia". •My ultrasounds; EEGs; & blood work aren't normal • The doctor who interpreted the last eeg said I need further testing and that imaging should be done but she disagreed with her and the person who reviewed her interpretation. •I have a ton of scar tissue near my internal jugular so my cardiologist ordered ultrasounds checking for thorasic outlet syndrome which showed abnormal blood flow but ruled out thorasic outlet syndrome so I'm having upper body nerve conduction tests soon •This started long before I experienced severe psychological trauma •Meds; CBT,CPT, DBT, talk therapy, etcetera haven't helped •My Psychiatrist, psychologist; GP; & Cardiologist disagree with the diagnosis •I haven't had any imaging of my head •I've also had 8 concussions from car accidents, fainting, sports, etcetera and my cardiologist thinks the pins and needles sensation is nerve damage since I've got issues with hips, shoulders, pelvis, collar bones, etcetera subluxation and dislocating. I've also had multiple surgeries and have extensive scar tissue in the areas that have the pins and needles. My cardiologist and pulmonary docs think lack of blood flow to my brain could also be causing some of the symptoms. •lastly some of the things he's contributing to FND are attributable to conditions I'm diagnosed with that are not controversial.