Maybe one thing that would help would be to prep as much as possible ahead of time (like on the weekend maybe while your LO is napping?). You could get all the fruit and veggies you like and wash, pre-cut them into sticks, bag them in individual serving sizes, and then maybe some hummus to dip the veggies in. Also, things like string cheese, individual yogurts, individual servings of almonds - all of those are healthy and are pre-measured for portion control...
Do you have a few meals you like that are really healthy? Like grilled chicken, fish, veggie lasagna? You could make ahead meals on the weekend, like broil a bunch of chicken w/ lots of seasoning, and then reheat as needed during the week.
Also, try to cut out all the soda - even diet - even though it doesn't have calories, it can affect your perceptions of caloric intake and you can overcompensate later (subconsciously) - and just drink lots of water.
Also, maybe try to incorporate some strength building exercise in addition to walking - free weights, squatting and toe raises (can be done holding babe), pushups, crunches, etc...