That's always a danger. But if you need help, it's best to get it than to avoid it out out of fear. I don't want you to go too many nights without getting any sleep. I'm sorry if that sounds a bit like an order, but I'm just concerned about you.
I think you just have to show some willpower. It's true that dependence on them can develop if you take them over a long period of time. But ideally, you wouldn't be taking them forever. I'm not saying they'll take away all the nightmares, but hopefully you would get some rest, while you deal with the psychological factors of this during the day. If you think you're starting to grow too dependent on them, you cut them out and look into other methods to deal with this. But at least give them a try.
I think you should. There's nothing to be ashamed of about seeking someone else's help. And if it doesn't work out, you can at least say you tried. But yes, I would recommend going to a psychologist or psychiatrist first, and see what their opinion is.
I should take my own advice. Funny how we can say things to people and not follow them ourselves. :/