I know how you feel somewhat. I haven’t been able to get lucid for a while now.
One thing I can say will help is stop saying you can’t. You can have a lucid dream and you will have a lucid dream. Just keep trying!
I have read of some people that didn’t have their first LD for like 2 years after they started trying, but in the end they had one, and it only gets better from there. Just keep at it and don’t get discouraged. You will have a LD, and it will be epic. Look here for some motivation.
You could try reading some peoples DJs for inspiration too. WritersCube has an amazing one for example.
What all have you been doing to try and get lucid?
Just please keep trying. I want to hear of your success.
Good luck and great dreams,
~Dreamjutsu~