I have severe depression,anxiety and insomnia... i just wonder is it ok to take 50mg of trazodone and 2mg ativan at the same time.

Yes: Yes, it is OK to take both of them together as needed for insomnia and Ativan for anxiety. Ativan should not be used on a continuous basis as the risk for tolerance and dependency can go up. Adequate sleep hygiene: avoidance of caffeine, heavy meals, vigorous physical exercise and stressful activities less then 2 hours before bedtime can help. You can also try CBT for your conditions.

Better not: as both would interact producing untoward side effects, usually use lowest effective dose if need be together and under doctor's supervision, kindly revisit your doctor/psychiatrist and keep the follow up for your own good, wish you wellness