5'8" and trying to tone up and lose ~ 25 lbs

Hello everyone. I'm a 28 year old stay at home mom of 3, and I currently weigh 178 (5'8"). I have a large frame and would like to get down to about 155. I had my last baby in sept. (my last 2 kids are 11 months apart in age), and I have been back and forth with exercise/nutrition for the last 10 months. I AM sticking with it this time, and I really like how easy it is to stay accountable with the mfp app.
I started my latest attempt 15 days ago. I've been doing the 30 day shred and training for a 5k in sept. My starting weight was 186, so I've already lost my water weight and I'm ready to take it off slowly and steadily from here on out. My husband works nights and weekends (about 60 hours a week) and sleeps during the day, so I'm pretty much a "single, married mom". I tend to want to sit and eat once the kids are all finally in bed, but I'm trying to stick with popcorn in the evening. I know I should just go to bed earlier, but I really enjoy that alone time!
I really enjoy exercise and played sports throughout high school. I've run a 5k and 10k in the past (about 3 years ago) and I liked how they brought out my competitive nature. This time, I'm trying to compete with myself and my own goals.
Best wishes to everyone trying to change their lives!