Again, without specific measurements, it's hard to ascertain your calories. I don't mean to be a nag though.
Instant oatmeal...I'm guessing it's about 150 calories?
40 calorie toast is dry? So that puts you at 190 calories for breakfast.
Greek yogurt....is it non fat? Then I'm guessing 100 calories. Almonds. How many? 207 calories in 1/4 cup but again, I don't know how many you're having.
Lunch: Turkey sandwich...2 slices of that 40 calorie bread? I'm going to guess your 1/2 sandwich is 300 calories with another 30 calories for the celery. An apple is about 95 calories, an orange about 80.
Is the 4 oz. of chicken breast? thighs? with or without skin? Veggies are fresh or cooked with oil? Sweet potato plain? 1 cup of sweet potato baked without oil is 180 calories.
Protein shake...there's no way I would attempt to guess how many calories because they differ so much.
I would recommend you track your calorie intake for at least a few days just to get an idea of how many you're having. It's really a fine line between losing and maintaining or gaining. It's easy to go over, is my point. Given that you're frustrated about your weight of weight loss, it would make sense to see where you're at with calories to see if anything needs to be tweaked.
Best of luck to you.