You are talking about "terminal insomnia" (waking up and not being able to go back to sleep) rather than "initial insomnia" (not being able to fall asleep the first time), correct? Either way, you should probably see a doctor about doing a sleep study if it doesn't get better. Trazodone is the most sedating SSRI you can find (it isn't great with depression, it's used mostly as a sleep-aid). So, I don't think the Trazodone is causing it. See a doctor to rule out causes that aren't mental health related.