I'm sorry to hear you've been struggling not only with the pain but also with getting a diagnosis, that's definitely something a lot of people with chronic pain face, and it makes getting any sort of support so much harder.
I wouldn't be able to tell you if things will get better or worse, or how your pain compares to mine or anyone else's, because each condition, and body, are different, but by the sound of it it is probably something you should be keeping an eye on and continue seeking help with, since it seems to be having a serious impact on you and you shouldn't have to just put up with it.
I know how hard it can be to try and navigate the medical world and deal with people who think they know so much better than you (even though it's your body!), and that this is easier said than done - but try not to feel invalidated by their lack of understanding.
Have you got even an idea of what your condition might be? Finding a community of people with similar conditions/symptoms (my pain is mostly musculoskeletal in nature, so unfortunately I wouldn't be able to point you to anywhere relevant) can be a great help since they might have resources and tools you wouldn't know of otherwise, and even advice or information you can take to your GP to back your position.
I hope that helps some, I wish I had a more definite answer to give, but either way, you have my virtual support.. 💙