I feel like something is off

I feel like something is seriously off. I don't even know what it is, or what it could be, but something just feels wrong. I feel sick to my stomach, like something bad could happen at any moment, but I don't know what would even happen. I feel so stressed and scared right now and I have no idea what to do, I can't get my mind off this feeling. I feel almost as if we have shifted into the wrong timeline, and I'm worried about what to do in this timeline. If anyone could please help me stop worrying, I'd really appreciate it forever.