e coli is in so many foods that basically every one will have it at some point, there are different strains of the bacteria so it sounds as if you have a mild version, ecoli is very treatable if caught early so you shoul be fine, a majority of food illnesses are related to ecoli,
there are many ways it can be spread, the most common being under cooked beef, or undercooked chicken
with you taking the antibiotics you will be fine:)
UTIs are caused by a couple of different bacteria, and e.coli is one of them. It's normally found in our digestive tract (and on our vulvas), and is the most common cause of all UTIs--like 70-80%. So while it sounds scary and weird, all this means is that you just have a plain old UTI :-)
Most likely the way that the E.Coli got in the Uninary Tract was by wiping from back to front when you go the the bathroom. It isnt a major deal, just a UTI that some antibiotics can easily get rid of.