Hi Maddiea,
Welcome to the forum. Yep, the process of trying to get in front of the right doctor and know for certain what's going on is really tough - and would probably qualify as a saga for a lot of the people here - but keep on pushing, so that you can rule out anything else, and experience a bit more clarity. We really have to be our own advocates with this condition, and while that's insanely frustrating sometimes, it can also be kind of empowering.
Speaking of empowerment, if I were you, I'd get straight on adopting all of the self-management lifestyle changes that can help with fibromyalgia. The post that Sunkacola shared above is a fantastic place to start - it might all seem trivial at first glance, but with dedication, these things can make a huge difference to symptoms. The advantage is that, no matter what is wrong with you, doing things like stress management, pacing, improving your diet, working on sleep hygiene, and so on, will all benefit your wellbeing. Certainly with fibromyalgia, the more we can tune into our body and take control where we're able, the better. There are sadly no quick "do this to be cured" fixes, but there are little layers of improvement that we can stack up towards feeling a lot better.
Good luck with everything - please do let us know how you get on with your diagnosis process, and ask any time if you have any questions, or just need to vent!