Greetings ! Welcome to the site. I am sorry to learn about your condition and I empathize with you.. Well the root cause of your insomnia and poor result from the use of temazepam is the fact that you have been taking venlafaxine at night time which many times backfires by causing insomnia in the users, therefore the best way to overcome your lack of sleep / insomnia is to shift venlafaxine to the morning hours , say anywhere between 8-10 a.m and simultaneously continue to take 10 mg of temazepam at night time ( no need to overload with this drug as being a benzodiazepine class drug it has abuse potential) and hopefully within a few days time your normal sleep pattern at night will return. Other than this change, you also need to practice proper sleep hygiene which includes -- avoiding heavy, oily meals at night, wearing loose cotton clothes while sleeping, having well ventilated room, avoiding tea/ coffee/ alcohol at night, taking a warm shower before going to bed if possible, avoiding late night television or music instead reading book/novel, changing room or side of bed for some time, maintaining sleeping and wake up schedules, regular exercise. So kindly do the needful and you shall begin to appreciate the positive outcome with return of good night sleep in the next few days. I hope this helps. Wish you all the best. Regards..