D.B.
I'm a nutritional consultant & educator, and I can tell you we see this a lot. Lots of people have these problems, sometimes from the bacteria and sometimes from the added diary, sometimes a combination. You just don't know what's in most commercially prepared products, unfortunately. You probably gave your system a real jolt. Some people have the gas/nausea stuff, and some get the diarrhea/lower GI reaction.
You also don't know what's going on in your digestive tract to begin with. Different people have different amounts of "sludge" coating the walls of their intestines (and it has nothing to do with whether you "go" every day or not - sort of like how blood still moves through arteries covered with plaque!). I have found that achieving digestive health is best achieved with a comprehensive product with both soluble and insoluble fiber (hard to find in the right ratio) plus herbs, digestive enzymes, and other key ingredients to help you achieve balance. When you just put one ingredient in (e.g. probiotics, or a plain fiber product), you can get a real upset that's worse than the deficiencies or problems you were trying to fix.
So I would stop the probiotics entirely, stop all dairy, and stop adding more things into the mix. I know you want relief, but the Prilosec, Gas X, Tums and everything else is just continuing to upset the balance your body is trying to return to. I can help you establish a balance but I'd have to know more about what else you are doing, and what made you want to add the probiotics to begin with (general health, or to treat a problem). The metallic taste may be related to the start of detox but there's a better way to do it that's not so harsh.