DAE get a terrible taste in their mouth sometime that just won't go away no matter what, ruining all culinary experiences for the day?

Today I got it in the morning after brushing my teeth and eating a perfectly normal sandwich (whole-grain bread, Creme Bonjour, meat, cheese, mayo and cucumber) about 20 minutes later. I was eating the sandwich and noticed this metal-type taste in my mouth that didn't feel it was coming from the bread but rather something reacting with the bread in my mouth. I finish the bread and don't think much of it.

After some time I eat a snack and drink some water and it comes back, and with it memories of this having happened a few times before. The water tasted pretty neutral but the snack again had that taste to it, as if it was at the back of my mouth taunting my every bite.

I can't quite explain the taste, it's like iron mixed with fluoride and bad breath, with the bad breath being a taste rather than a smell... the whole thing is only a taste sensation. I haven't ate that much lately and I have a flu, which I believe add to the issue, but I don't know if it's my tongue acting up or something actually mixing and catalyzing to form a bad taste.

Any thoughts?