My form link is not working

My date to bring the application down is 5/16/2016 at 11:59

- people cannot access my form it says Form no found.  see photo below. 

where do i go to either correct the disable date or change it?

Also, can i add a field and to the existing form without messing up previously submitted data.

I checked your form's link which is this one https://www.jotform.com/60893551518159, and it seems to be working correctly:

However, I see that you have set your form to have a unique submission based on both the IP and cookies of your users. Here's a screenshot to where to find that limit you have set:

Here's a guide about that submission limit: https://www.jotform.com/help/64-How-to-Set-Unique-Submissions-on-a-Form. Basically, your users who submits the form using the same browser and computer won't be able to submit the form multiple times. Only once.

Let us know if I misunderstood your problem.