I remember getting bad side effects when I started on Lyrica. Headaches (I am not typically a headachy person, so this worried me). Constipation for the first time in my adult life. At my 2week follow up appointment I told my Doctor that I didn't think these tablets were right for me, the side effects were strong.
He asked me to stick it out, that my body would get used to the new drug. So I stuck with it. A few weeks later I told him the symptoms were improving a little but the pain was still there. Not as strong mind you. So he told me to take a higher dose. I thought he was crazy but I did it anyway.
What I found is, although on a higher dose, my symptoms did not get any worse. I found this to be the case as we slowly increase more and more until I was almost pain free, enough to live quite normally again. At about that time the symptoms went away.
Your experience may be different, but that is how things worked out for me. I stuck with it, through the nasty symptoms, and it fixed itself.
Ohhhhh and to help with the hunger symptom, my Doctor also put me on Duromine (an appetite supressant). Yes, it's a nasty drug, horrible. But, I took it for a few months while my body settled into the Lyrica, and it worked to stop, and I mean completely stop, all hunger.
I too hold fluid, your post has me wondering if a Duiretic might help me.
Hope you start to feel pain relief