Eating ALL of the calories after intensive workouts?

My workouts are usually pretty intense.

Either I do long runs (60 - 90 minutes, HRM in the mid- to upper 80's), or shorter runs up and down a roller coaster hill (laps up and down, hill gains 100 feet of elevation in .3 miles, HRM in the low to mid 90's for 4 or 5 miles/45 - 60 minutes). Every once in a while I give myself a break and only run 3 miles, but then ramp up the pace so HRM is in lower 90's.)

In spite of bumping the intensity of my workouts up to this level since Oct, I'm stuck on the scale, having only lost about 4 pounds since then. Once starting MFP, I realized that a typical net calorie day has been around 800 cals on workout days, or 1500 cals on non-workout days. (I work out 3 to 4 times per week.) MFP wants an average of 1200 cals per day.

People in my life (with first hand knowledge of how I eat and work out) agree that the math is not adding up.

For background, I still have 30 pounds to lose to achieve pre-baby weight...and have gone through multiple workout spats these last 10 years but they never move the scale, so after 6 months working out each time I eventually lost interest. I've been working out since April of this year and have lost only 9 pounds in total since then (30 to go). This time, instead of quitting the workouts, I bumped up my cardiovascular workout intensity (in October) because I discovered how much I enjoy running. Losing only 4 pounds since Oct after ALL of these miles and this intensity is really discouraging.

So my question to all of you who have been losing weight and also do 1,000 calorie workouts....do you eat them all back? What works for you?