I can't stick to my calories.

I was similar to you - eating between 1500-2500.

Here is what worked for me
Logging everything that I ate, going back to my diary and seeing what worked and didn't work.
I noticed on my 1500 days, I always had a smoothie made with almond milk, spinach, berries and flax seeds. So I started adding those everyday.

Then I started working on my problem areas
1 - going out to lunch with co-workers - I started bringing lunch and eating with other people that eat in our break room and then going out for a 30 minute walk. I enjoy this just as much as going out and it is easy and healthy
2 - snacking after dinner - smoothie instead of chips
3- snacking after lunch at work - have a mini meal of Morning Star Farms chicken nuggets, some cut up vegies and low - cal dip - that is ~250 calories instead of the 800 cheese, crackers, cookies that I was eating
4- going out to dinner with friends - try to do another activity - walk, go to an art fair, get mani's together - anything besides eating.

good luck!