I too had horrendous pain prior to gall bladder removal. Before diagnosis, I had my first attack on holiday and thought it was my heart. It was only once I returned home, visited my GP who referred me to the hospital, that I was scanned and diagnosed.
I'd read horror stories about constant diarrhoea afterwards, but that never happened. I had keyhole surgery about 6 years ago and have been totally fine since - apart from intermittent symptoms from my hiatus hernia, diagnosed a couple of years later. I can and do eat fatty foods, but as I'm trying to lose weight and get rid of visceral fat, I'm restricting that somewhat (apart from the odd bowl of whipped cream, that is).
achushla really sorry you're suffering so much. As doctors can't help, could you consider complementary treatment such as a medical herbalist, for example, a naturopath or homeopath? Some might call it bunkum, but might still be worth a shot - you never know.