Being that you're a night shift nurse, you're already burning a ton of calories. You should probably cut your workouts way back. If you want to still work out frequently, maybe try for 45 minutes 3 days per week. Definitely increase your fluids.
Get plenty of sleep. Increase your calories to AT LEAST 1000 per day, because with what you're burning between work and working out, your body likely thinks it's in starvation mode and it's hanging on to everything it can. If you decrease the workouts a bit and increase the calories a bit and increase your sleep and fluids, you should be able to wake your body back up and start losing again.
Also, what are your stats? What surgery did you have, what was your starting weight and bmi and what is it now? You lose more and faster when you're heavier. As you get closer to a healthier and "normal" weight and bmi, the weight comes off slower.