Am I eating enough??

I am 34 5 feet tall weighing 119lbs. My goal is 108lbs.  I eat about 1000 - 1200 calories a day; however I am starting to feel extremely tired.  I run 3 times a week  Monday and Friday 3 miles at about 12 min/ mile and Wednesdays I increase my miles weekly for the marathon training.  This wednesday I am at 5 miles at 12 min/ mile.  Tuesdays I do mat pilates.  Am I not getting enough calories, I am also not loosing any weight, I am stuck

You are definitely not eating enough. An adult woman needs to eat at LEAST 1200 calories a day to function, and that is for a sedentary female. You should probably try increasing your calorie intake, it may even boost your metabolism and help you lose some more weight.

From what I have been told when you drop your calories that low your body goes into starvation mode and you don't lose weight. If you do start to lose weight as soon as you eat your body converts it into fat because it tries to store as best it can so I would raise your calories asap.  I am not an expert but I know for sure that anything below 1200 calories is dangerous especially if you workout 4 times a week.

This is the information this website says for your current weight, age, height, and goal

Calories Needed for Goal Weight

Results

You should consume about 1,349 calories a day to reach your goal weight of 108 lbs This is at a reasonable weight loss average of 1 lbs per week, which should be reached by February 24, 2010.

Experts recommend weight loss at the rate of 0.5-2 lbs/week. Remember that this estimate is based on your body weight, height, age, gender, and activity level. It may vary slightly depending on other factors.

Generally, women should not consume any less than 1,200 calories per day, and men should not consume less than 1,500 calories per day.