Constant food cravings

I suffer from this as well, and I honestly think it's just a mind game, at least that's what I tell myself. I always keep fruits or vegetables on me to help curb my cravings.

Cravings mean you feel hungry. This is a novel experience for a dieter. When we are getting fat we are eating more than we need, so we never get hungry. If an overweight person misses a meal their body has a ready store of fat to use.
Once you start dieting your body starts using up the fat store, so the messages of hunger will start to come through.
When do you get the cravings?
It is good (and normal) to feel hungry before a meal. But perhaps your diet food doesn't seem so alluring? Try some new recipes. There are loads on the blog of this site.
Are you leaving it too long between meals?
A snack at mid morning and mid afternoon might help. (Though keep within your calorie limit)
Learn to savour that feeling of hunger. It means your diet is working and you are more in touch with your body. But just don't give in to the gremlins in a completely different part of your mind that try to translate a simple message from your hormones, 'I'm hungry now, time for a snack.' into 'Get me into a McDonalds NOW'.

Craving, hunger is part biological need and part conditioning. After your biological need is met, ie you have enough nutrition, there's work to do to retrain that conditioning part (ultimately ignore and be ok with it). Again, it's work.