Dear Desperate, 
Don't panic. Experienced writers remember what they learned in the Boy Scouts : Be Prepared. Stop trying to fix the script as
you go along. It won't work and you'll only make yourself miserable! Take a break.  Take a shower.  Make a cup of tea.  Then, sit down and write a one page monologue for each character - just for yourself. Story IS character .  If your story stops, that can
mean you just don't know enough about your main characters. 
Don't be discouraged.  Writing is hard work - even for pros.  Have fun! Good luck! Karyl 

Are you having a script problem? Maybe I can help.  E mail me a short note.