I have been doing something simular to the honey that you mentioned. For the Tarceva rash on my face, which wasnt much of a traditional rash, but huge painful acne whiteheads and cysts with very dry skin. I made an aspirin mask, which I make and use daily and it has helped this rash an unbelievable amount. I mix about 4 generic uncoated aspirin with a few drops of water til they dissolve. Then add a few drops of honey and make a paste (feels gritty like a scrub). gently massage it over slightly dampened skin to remove the dry dead skin and leave it on as long as you want - it rinses easily with warm water. its soothing and helps with the redness if youre consistant with using it. Aspirin is a pretty good acne medicine too - maybe youve heard of spot-treating a pimple with a dissolved aspirin. Of course if youre allergic to aspirin id stay away, but its s worth a try, you probably already have all the ingredients anyways! I also treat the rash with a mild glycolic acid in the morning after my shower (aspirin mask before shower) and differin at night. The aspirin mask seems to speed up the process. (my skin is better than it ever has been at the moment, clear and smooth after 3 months of a horrible acne rash)
I started to get a rash on my chest too and i actually have a little aspirin mask on it now.
As for the upset stomach, I havnt found anything OTC that helps it. I just have to watch when I eat since it seems to get upset about an hour after a meal.