A few months ago, your email could have been a cathartic outburst of my own! I was entertaining such feelings after almost a life-time of healthy eating followed by a whole year of debilitating sickness that put me out of work, out of money and out of life. And yes I was trying this and that with only mediocre results.
It was only when I put a whole system in place that it all started to turn around. 3 months later, I've gone rapidly from bed-ridden 1 week in 4 with constant nausea and hellish skin problems, to no sickness/nausea and very minor skin blemishes with the occasional mild indigestion. And getting better all the time with energy to do stuff!
I think no one solution, such as liver flushing, works in isolation. You need to address the whole system, take in the big picture and work through in a progressive and systematic way. Are you familiar with Doc Sutter's work? See his forum. He's worked out a very do-able and logical system and this underpins most of the system that I put in place for myself. It's easy to follow because you're not doing everything at once but working through one thing at a time in the most effective sequence. And it worked for me - noticed the change within the first month. Barefoot Herbalist forum is also excellent in addition.