What could cause this in my 7month old baby?

Starting May 27th she was back and forth the hospital for being wheezy, she was put on medication for bronc. then a few days later off that and on a steriod and another type and a puffer with the dates of may 27th and june 6th the meds didnt seem to work once those doses was finished she seemed to come back to normal by the 2nd day of no meds but she has had gas like crazy non stop all day every day since. Also within those dates she has thrown up twice and i mean covered herself and me. NOT like her. she usually spits up like normal when burpt but that has stopped the last few months. Sooo.. with that said... last night was feeding her and getting her ready for bed. she was half asleep in my arms when all a sudden outta no where with no signs she throws up soaking us both the she started to get warm(no fever) and alil shakey.she was drooling alot but the last few days that has stopped.Also since shes been having this gas she doesnt seem to be drinking as much. a case( 12 cans - 385mL each) of formula has lasted us since june 4th. and it is now the 16th she got 3 cans left. Off and on during the day she seems warm but no fever. last night at the hospital they left the oxgyen reading thing on her cuz it was reading 94.. Any idea why shes like this???