Low ANA, is a good thing as they use it to diagnosis lupus. You mentioned having an ovary removed. If you have cysts on your ovary they can cause a lot of pain. So once the ovary is gone see how your pain is then. If it continues go see a rheumatologist. This is the only doctor that can diagnosis fibro. He will test for lymes and lupus. Also RA and other conditions. Sometimes getting that diagnosis can take years, because these types of illnesses all start out with the same types of symptoms. And often times in the early stages all the tests are normal. That is why doctors often label you with depression. It is a time of keeping your cool and trying to remain strong and positive. It is not easy and I can tell by your voice in this post you are sad and discouraged, each time the tests are normal. This is normal human behavior. You just want to know what is wrong so you can make a plan and deal with it. But you think you can't plan because you don't know. This is wrong thinking.
You can start right here and read some of the older posts. Everyone coming in here has been given some coping skills. And the forum is filled with posts from people sharing their tips on dealing with pain and fatigue. You start a plan by learning the coping skills and seeing what works for you, then build on that when you get your diagnosis. If you get depressed find a counseler you can trust and work on improving your mental out look. It does not mean your crazy, it means you are taking charge of your healthcare. It makes you stronger and more confident in facing what lies ahead.
And don't forget to share here and use the vent topic when life gets to be to hard to handle alone. We are here to help you in anyway we can to get through the ups and downs of getting that diagnosis and beyond. Good Luck!