how fast is listeria affective?

I woke up this morning for my parental appointment, ate cereal, drank way too much water. my belly felt too full and slightly sick which I know is cuz I drank way too Much water. anyways I took a nap when I got home, got up from bed to pee and got this heaviness in my stomach then I sat down and ate a lunchables, cheese is pasteurized, and it was all so small, then I drank a malta. then like 2 minute's after finishing I got diarrhea and now my belly doesn't hurt, just the horrible gas ive had all day that hurt to come out. milk doesn't sit right in my belly sometimes. I'm obviously overreacting but its not listeria right?