Can trazodone cause rebound anxiety? Been on it for 3 weeks for insomnia. Helps me sleep, but I wake up feeling really anxious. What's the deal?

Rebound anxiety. Good question--what's the deal? A good place to start to get you answer is with the doctor who prescribed the medication for you in the first place. I would be talking with that person rather than looking for an answer online. Is there some reason you aren't talking with your doc?