Welcome to DV!
I've been working on the same things lately, I struggle a lot with the dream ending into a false awakening. I've found two things that have helped me, maybe they'll help you too.

I like to DEILD when dreams end prematurely, this is nice for saving a lucid dream but I feel like I have to keep doing it to stay in a dream.

I've also started using the affirmation that I don't have to wake up yet. I use it in dreams and in waking life. I like to walk around when I'm awake, pretend that I'm in a dream, and marvel at how fantastic it is to not have to wake up yet. I do that until I feel comfortable knowing that I can stay in the dream for a long time and that it's not going to end anytime soon.

I hope to see you around!