What Causes Sudden Dizziness After Excess Fluid Intake?

was roofing a few days ago and it was about 95. i was drinking a lot of fluids but randomly i got really dizzy and faint. i couldnt see strait came home felt like i was going to pass out threw up three times. its been two days and im still getting really dizzy and feeling like im going to pass out. been drinking a lot of water and eating a lot. im curious as to why im still feeling like this.