If you're spitting out mucus, it means that your stomach is protecting itself from something that you've eaten. Since you're not eaten gluten, my guess would be animal protein. The results of eating animal protein don't always show themselves immediately, but build up over time. You've already eliminated dairy, but you don't say that you've stopped eating meat. I think that's something you should try - I was only able to heal after I became a vegetarian. Meat is one of the most acidic, clogging foods you can eat and the body can't digest it.
Also, one Liver Flush isn't enough. It's not really going to do much for you except start the process of cleaning the liver. You need to completely clean out the liver to see results. It's the most effective way to heal yourself, but it takes time.