My dog acts so weird!?

It sounds like your dog is timid, unsocialized and untrained. You need to get a consultation with a behaviorist. They should be able to work out a socialization and training plan to make both of much happier.

She is insecure, fearful and needs more exercise.

She hides in the corner because she feels vulnerable, I had a dog like this and a travel crate or wire crate with a blanket over it would be a nice safe den for her. Don't force her in and shut the door, she will never forgive that. Leave the door open, put a blanket in for comfort, give her treats if she goes inside.

Socialize her more. Take her to pet stores where people love dogs. Bring your own treats along. Either use the treats to keep her focused on you and ignore what scares her, or have new people offer the treats. Treats should be offered with a flat hand, ask people not to stare at her and offer treats from the side not head on. This is less threatening to the dog.

If she barks/miss-behaves, use the leash to correct her. Reward good behavior.

If she destroys things she could be either bored from not enough exercise or stimulation or feeling anxiety. Try walking her more or getting her a new stimulating toy. Like one of those Kong toys you put food in and the dog tries to figure out how to get it out. Or if you got her from a different home or a shelter, she could have some sort of fear you don't know about.

Don't hit her but you need to show some discipline. Show her that you are in charge; not her.

maybe you should take her to the Doctor