1200 calories for maintenance?

I am a short, underweight sedentary female. My app says my bmr burns 1152 calories a day. With activities it increases to about 1200-1300 calories a day. I just want to say that staying under 1200 calories is easy but I have to admit because of that I can't enjoy normal meals, I didn't get to eat desserts for months and I have to eat 1 chewing gum while working (office job) for breakfast until I come back home (which is about 4pm). Everyday is the same but today I came back at 1pm, for lunch I ate an average serving size of chicken, fish and rice with veggies which turned out to be about 900-1000 cals? (I found out that the olive oil i had was extra so yea instead of being 400 calories it went up to 900 calories. I was so disappointed so I didn't eat until like 8pm. I then had 2 apples but then suddenly started to feel nauseous so I ate 1 slice of toast with cheese (all of these were 280 calories). It makes me jealous of other people enjoyinh everything they want without gaining weight (and they're also sedentary like me) and then there's me trying to eat small amounts of food and still struggling to maintain my calorie intake. I'm starting to wonder whether 1200 calories is too much for me because I've been eating 700-900 calories for some weeks except for yesterday (1300 calories) and today (1200-1300).
1200 calories for maintenance?
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