Just be honest with him and if he is not fulfilling your needs then you may want to look for another doctor to help you out. One thing my doctor told me is that you must deal with real issues. Meaning that by him prescribing me more benzos or something stronger wont make my problems go away...they will just make me forget about them for awhile. You need to solve these "real" problems. No amount of drugs will fix it for you.
The trazadone should work in the meanwhile but work on your problem with other things like excercise, vitamins, don't drink, stay away from illegal drugs, etc. Also work on a new sleep schedule and try to stick to it every night. Ask him about other "non-addictive" sleep meds if the trazadone is really not sitting right with you. Tell him that this lack of sleep is putting you in a bad mental state and is making you want to do drugs again because you are unable to sleep. That may make him a bit more receptive to prescribing you something else, but you need to at least give the trazadone a try first as it had always done the job for me.