Thinking of going up to Moderate?

Options
I have been eating around 1800 calories per day (plus whatever I burn off at the gym), as that was the recommendation for Light activity. I chose light because I do 40-60 minutes on the elliptical 3x a week. But does your day to day life matter? I am a handler at a dog daycare where I spend 6 days a week constantly on my feet. My job consists of cleaning, moving large metal crates, and chasing around crazy puppies.

Now I know there are much, much harder jobs out there, but I am in pretty bad shape at the moment. Back when I was eating easily 3000 cals per day (yeah, I know...), I was already exhausted by the time I got home. But lately, at 1800, I find myself getting extremely tired in the middle of the day, to the point where I'm worried I might collapse.

Does my system just need to get used to making due with less? Or should I think about upping my daily goal a bit?