Separation anxiety

It seems as though my baby has separation anxiety. I went out to a movie last night and thought a couple hours away couldn’t do any harm, well that’s what I kept telling myself to not feel guilty for leaving her 😕 I never get out of the house so I figured this one night would be okay. She’s almost 4 months old and I still don’t like leaving her at all. I’ve noticed the way she gets when other people come around her or hold her, she will scream and not do well at all and only wants me. Well last night I fed her, changed her, got her ready for bed and went off to the movie. She screamed forever and wouldn’t calm down when I left. She wouldn’t go to sleep, didn’t want to eat, nothing. I was upset because nobody contacted me but they said that they didn’t want me to come back home and that I’ve spoiled her (these are my in-laws btw) I was like still, if I let you watch my daughter, you need to tell me things. I might be being over dramatic but my baby wouldn’t even eat and wouldn’t calm down at all, she was so upset and uncomfortable. It broke my heart. I got home and gave her lots of snuggles, I instantly picked her up and she just rested her little head on my chest. I felt so terrible. I know I need to get her used to it so I can get a break every so often but my baby literally starves herself and just doesn’t do well at all and I feel so terrible.. I know babies get this way and it’s normal but it just hurts my heart and makes me not want to leave her.