Hey Erin,
I have no idea if those symptoms are related to IC. But what I can tell you is that I used to have the same problem. From the time I was 4 years old until I was 16, it was never diagnosed. I went to the Mayo Clinic in Rochester, MN when i was 16 and they said my bladder could hold more than the average person, just like you said, and the way to fix it was to retrain my bladder. I was instructed to drink the recommended 6-8 glasses of water a day (for me, this is still impossible) but as long as you drink water and also cranberry juice when you feel a UTI coming on, and to make sure to flush yourself out every 2-2 1/2 hours (or as close to that as you can get it) even if you don't feel like you have to pee. At first, it was so hard. I felt like peeing when I didn't feel the urge to go, made a UTI come on. But after awhile, with a lot of help from my mom, it eventually worked. Now, I HAVE to pee every 2-3 hours. And I know when you are suffering with a UTI, anything that's not a quick fix is not going to help you right now. So while you're hurting, if you need OTC meds, I really like AZO Standard. It is a OTC version of Pyridium (what docs will give to relief the pain and urgency when you have a UTI). AZO can be bought at just about any pharmacy. The only thing, it turns your pee bright orange but that's good cuz it means it's working! Another thing, it will only hold off the pain and buring, not treat it. So if it's that bad, you will still need antibiotics. I hope you feel better soon! And please let us know how you're doing and what you find out. I did have a doctor mention IC once when I had a horrible UTI so I'm curious too.