Long Distance Runner & Questions about Calories.

I'm having a bit of trouble here since I have discontinued personal training and have been working out my own exercise regimen.
To have an idea of my exercise:

- I cycle at 9-12mph for 40min. daily
- I run 6 days a week with a day of rest and I go in the pattern of 4 miles, 6 miles, 8-9miles, and 10-11miles.

I'm 5' 7" weighing at 163lbs with a 22% body fat percentage (weight is currently fluctuating due to hunger). I'm a pescetarian so I'm mainly consuming pb2 (peanut butter powder) with fruit or celery as my snacks and regular meals which consists of bread or oatmeal, fish, and 2 servings of vegetables. (about 340g or less of carbohydrates daily)

...however MFP is saying that i need to consume only 1360 net calories which I'm finding almost impossible since I'm active and constantly hungry. I usually consume about 1600-2000calories daily.. My goal weight is 140 or less if possible so that I am at a healthy BMI... any advice? or anyone with a similar experience?