Endocrinology question ; need help; Dr won’t give referral

My Sr won’t refer me to Endocrinology (I don’t have diabetes, but this was the only group with the topic of endocrine system. ). I know there are more extensive tests an endocrinologist can do to check my thyroid, cortisol levels and adrenal system. Since Aug 1, I have had the feeling of being incredibly dehydrated ( but I’m not) with a scalloped tongue, and moments of severe exhaustion… have moments where I feel I cannot function physically, or mentally nor verbally. ( I do have fibromyalgia and other issues as well). My skin and eyes for maybe ten years are dry dry dry. I have gained weight around my mid section ( apron belly) and I’ve not changed my eating habits at all. I am going for a cortisol “ test” , but at this point, my Dr is holding off on a referral, but I truly feel I need more extensive testing of my thyroid and whole adrenal system.