Jak, this is silly:
"...
Sometimes I do feel a bit of a fraud as others are so much worse, but I still like to think I have plenty of years ahead and want to be able to get a decent nights sleep and do the things I enjoy..."
...although many people go through that same negative thought pattern. The fact that you are openly sharing your concerns AND pain levels AND quality of life issues means that have a big problem that you need to fix.
You are ready to finally address the root cause of the problem, and I do believe you will be successful. Keep doing your homework.
As you can see, we are lucky to have some smart, caring people that were in your shoes. And now they are on a path of healing and wellness. You will get there too. Just keep "beating it up" until you get the answers you need to be ready!