Where to go from here with my script?

I was cooking up an idea for a book (my first) for about 5 years, I
had detailed characterization and backgrounds and outlines. However,
at a certain point I was discouraged from writing a book (I felt that
the story was almost too character and dialogue driven). Worried that
I might never write it... I adapted everything into a script which I
wrote in the past 8 weeks or so. I've spent a week editing and have
brought the number of pages down to 120 by cutting out everything I
thought was unnecessary (getting rid of characters, scenes, etc. from
the outline).

Overall, I think it's a alright/good script, it certainly isn't
perfect- and it would need a couple of more rewrites to be "great".
The idea, however, is original and the story is rich. At this point
I've had one family member read it, and her response was lukewarm- she
said it was well-done but the climax falls flat which is the worst
thing you can hear really (and it's true). I'm not sure what to do at
this point... I've hit a wall in terms of fixing the climax. The
things has been stuck in my head for so long that it feels impossible
to go outside the box. I also don't know where to go from here. Should
I register it? Send it out?