I haven't taken trazadone in quite some time, but to avoid grogginess in the morning, I would take 12.5 to 25mg. I remember waking up much more alert while still getting a good night of sleep. The best for me was actually 12.5mg. I know it is low, but this would help me sleep well while waking up refreshed the next morning.
Before giving up on it, you might want to try a lower dose and see how you respond to it. Just some food for thought.