Trazodone Experiences

[[JT...]]

Hi, 

I was recently prescribed Trazodone to help with severe insomnia (going on for 3 months now). They started me at 50mg 2 nights ago. It seemed to work very effectively. Was able to sleep several hours. Last night I took the same dose and was wide awake an hour later after getting into a restful state. I was simply unable to fall back asleep. My doctor said I could take as much as 150mg for sleep when she ordered the prescription. So... I took another 50mg. Again, I got into a restful state and then popped right back out of it and remained in a kind of state where I was fluctuating between being awake and in a weird kind of light (certainly not deep) sleep. 

Any idea why this would work the first night and then fail the second night at twice the dose? Do I need to go up to 150mg? What happens if I keep increasing and I'm getting the opposite effect?