Only at night? BabyGirl started her first heat at 5-6 months and she just gets a little sad and loses her appetite a bit.
To me it sounds like something physical is bothering her. Possibly a tail issue or maybe ears. My BabyGirl will snap at the air and circle around like she's mad and I know her tail or private bits might be bothering so I give her an extra cleaning and then she settles down. I feel like she has no other way to express her discomfort. Hope you can find out soon what it is. I know I get stressed out if my animals are stressed.