Boyfriends 6 yr old girl...help!

We started dating after I was going to start babysitting her. He fell in love with my affection for children (tons of love and experience)...well the first incident was when his 6 year old made me use the $50 gift card she gave me for my birthday on her. It got worse from there. She threw 3 hour tantrums banging down doors when he kissed me. Then, she started hitting and beating her dad. Finally, her teacher already sent letters through class dojo about her behavior, and we had to pick her up for tantrums. I put time, love and effort and the teacher bumped her up in reading and behavior. Things went to extreme after that. She began intruding our privacy. She refused to listen. She would not eat. I took her to a therapist but she never called back. She started getting in my face and being aggressive. The neighbor even said she was too difficult and aggressive with her child. No children like her because she is masculine and aggressive. I had a miscarriage and during the time I was miscarrying she wouldn’t allow her father to comfort me. Finally I left him after she almost hit me over her hair bow. Life was a nightmare with her and she took all my time. Is this normal?