In theory yes, you should not be on Temazepam long term and yes, you "might " get side effects and yes they "might" become a problem and they "might" not disappear if you reduce the dose or discontinue them.
A lot of "mights" there.
BUT....medicine is not about theory, it is about people.
Anyone who has known the disabling effects of insomnia and the depressive effects that it causes may beg for a compound like Temazepam.
You do not become addicted to this drug, but you may become dependent upon it.....two different concepts.
I agree totally with the post of JJ 21.54.
Sleeping tablets get a bad press.....probably in many cases undeserved.
I would continue the medication that makes YOU life tolerable and i am not convinced that the symptoms that you describe are a side effect of Temazepam.