Yes I've had that on and off throughout my life too. I never looked at my tongue, but what you describe does sound like colon and liver. I would seriously consider a Liver Flush which took away years of acid reflux quickly. I can't say how much it helped.
However, that being said, this sounds also like my girlfriend who has Candida. I'd also go over and check out the Candida Forum . You may be dealing with some yeast issues as well. At least I'd describe my symptoms over there.