Kirsty - hugs.
I had gallbladder problems when I was pregnant with the first set of twins. It was awful and painful.
I also just had to put up with it until I could have the darn thing removed the following February. There was nothing really that I found eased the attacks, sorry.
I sympathise. I assume you are doing all the low fat stuff already.
Unfortunately, your pregnancy hormones also set things off.

Hope you get some relief.