1998 Chevy Truck running funny

My truck is a low rider S-10 pick-up the other day i was driving a drove threw a havey water puddle, it cut off on me an would not start for awhile. i waited then started it up again it running and i can drive it but the engine light is blinking and it feels and sounds like its running off of three cylinders.its dragging along and making loud popping nosies. i change the oil and it ran alot better but it had so much water in the oil i feel like the engines gone already. so what should i do wait till it dies, add some electrial parts to c is its just that. but i really dont understand how it got that water in the engine when the intake is on top with the carburater