Help! My 7 year old suddenly has separation anxiety

Hello Everyone,

I’m in desperate need of advice. Recently my 7 yr old daughter has become scared if I leave the room or go out to do something quick outside . Some examples from this past week. I went outside to turn my outside faucet on to water my bush. My daughter was crying bad and banging on the door screaming for me. Tonight, I went out to my garage to my car to look for her sisters bottle and same thing, crying and banging on the door yelling for me. She even went as far to say she had to use the bathroom number 2 so I would come in and help her when she didn’t need to go. Another time I went to the bathroom and locked the door and she tried opening it and started freaking out asking for me and asking why I locked the door. Just yesterday I was gazing the car and she was banging on the window crying for me to come back inside the car even though she can see me pumping gas. Sometimes when I leave the room she will yell mommy to check if I’m there and then it changed from checking if I’m there to mommy just want to say I love you. Which I know she’s saying that just to check on me. She has also asked questions about death and if that she doesn’t want us to get old. I had mentioned this to my husband this morning and he said that she asked a weird question this morning asking if he was really her dad and if he was a real person. This all just started about 2 weeks ago when school started. I tried asking her if something happened at school or if someone was telling her things and she says no nothing happened and no one’s said anything. I can’t think of anything that I know of that could be triggering this behavior or why she is so scared all of a sudden. I am going crazy and have no idea what’s going on and how to help her work through this and how to handle this. Has anyone gone through anything similar and what did you do to help?