Just a thought: have you tried using plain ground psyllium husks instead of Metamucil powdered or wafers? I didn't tolerate the Metamucil wafers very well, but have had better success using the plain, ground ordinary psyllium husks. I add 1 tablespoon of the psyllium, plus 1 tablespoon each of flax seed and chia to my smoothies. (I also use kiefer as the base, since I'm lactose intolerant and it has a lot of probiotics.) I have seen a good thickening in my output since I started this process a few weeks ago. (I also take three Beano tablets with my smoothie to prevent blowing up like a balloon. It really helps me.)
I wish I could wave a magic wand and make your struggles go away! The fight gets old really, really quickly. My thoughts and prayers are with you.