Bad boobie milk?

😻💜
How long does breast milk warmed to room temp out of the fridge last? I usually warm enough milk for 3 feedings at a time and keep the bottle in the insulated bottle pouch in my diaper bag. But the last time i did this i noticed the milk smelled weird like formula almost? Not a sour smell just a strong formulaesque smell. Does this mean its gone bad? The info from my dr said room temp the milk is good for up to 10 hrs is why i do this but does that only apply to fresh milk not warmed up refridgerated milk? Baby is fussy a lot and now im worried its my fault for giving him bad milk :(. Please help!