So honestly yes, you'll have to eat more. A lot more.
You might look into science-based running training...i.e. you'd probably be doing a fast walk / light jog 4x a week, 1 "regular run" once a week, and then HIIT starting 2x weekly and then moving to 3x maybe. This is how I used to program for endurance athletes, and it's in all the personal training cert / manuals so should be easy to find a program online (and tell you WHY "jogging / regular runs" are terrible for improving).
So basically that would help improve your CC performance. I know it sounds counter-intuitive, but trust me...sometimes "less" really is "more." The HIIT sessions should be brutal as hell anyways, and it's unrealistic to train them daily. Again...google is your friend.
Since you didn't mention it...I'd assume you need to start lifting too. Probably want to do a 3x a week more basic strength-program at first. Doing the big exercises i.e. squat, powerclean, etc will transfer over to your athletic ability as well. I believe Rippletoe's starting strength would be a good point for an endurance athlete to get into.
Ah so yes, back onto the eating...
You'll want to take in a lot of carbs since you're probably burning a lot / will be burning a lot more. Healthy fats as Elvia mentioned are an easy way to increase the calories...cashew butter, peanut butter, extra virgin olive oil--the usual suspects.
Honestly I believe if you implemented all these strategies you could easily get up to 170lbs lean at your height, and with greatly improved athletic abilities. Within a matter of 6-8mos.
Good luck.