You only gave it thirty minutes before you re-dosed? The half-hour mark is when temazepam's effects only just begin to be realized. That's why, in the leaflet distributed with the prescription, it reads "Take this medication a half hour before bedtime." With no benzo tolerance, you're going to feel like a mess come morning - an ooze-like, amotivated blob of consciousness struggling to claw its way out of the muck. My advice is to be more prudent with your dosing, and even moreso given the laundry list of reasons why you might experience heavy after effects, such as being "scrawny" and having "no benzo tolerance" at all.
I've been scripted temazepam for a long, long time now for chronic insomnia. I find it recreational only at 30mg, 45mg or (*verrry occasionally*) 60mg. Anything higher, despite my concurrent scripts for diazepam and alprazolam XR (and thus a pretty decent tolerance to benzodiazepines) consistently induces a dysphoria I can only compare to zolpidem tartrate or one of its related Z-drug cohorts. Seriously, give it a try at 45mg next time and just wait, and see if you don't enjoy its effects more. With some drugs, less is truly more, and I believe temazepam follows this rule to the letter.
Let us know how your 120mg experience worked out for you. I'd be curious.
And IMO it is one of the stronger benzodiazepines (not by weight, obviously, but in terms of the profundity of effect). It can be very euphoric and opiatesque if the right dose is consumed!
Good luck,
~ vaya