afraid of the most trivial things

Not sure if this is the right subreddit for this.. I have a lot of anxiety but I've never been the textbook example of a person who worries over ovens left on or doors left unlocked or all the possible things i could fuck up in the future. Not a lot, anyway. It's not crippling.

Lately, I've had the most absurd fears. I randomly start feeling nauseous because I'm afraid someone will stab me in the stomach. I'm somehow anxious over my period being late, although my period just started a few months ago and it's perfectly natural for it to be late. I've never had sex either but my mind comes up with absurd stories about how I could've got pregnant anyway. The worst thing is that I feel that these fears are completely reasonable and could happen. On the other hand, it couldn't, because nothing feels real and I often feel like I could just walk over and stab someone and there wouldn't be any consequences, because hey, it's not real! My depersonalisation has never been that bad but it's getting out of hand..