I would suggest:
Add a hardboiled egg to your breakfast.
Have a midmorning snack, just a piece of cheese would be enough.
For your afternoon snack, maybe smear some peanut butter on your celery.
Overall your menu looks okay, but it may be too low in calories. If you run this in Fitday I would guess it would come in around 1000 calories. If this doesn't resolve, you should check with a doctor to see if there are other things going on here.
Life's a journey, not a destination.
It's easier to stay on plan than to get back on plan.