i made a change in text and other things in a form after of start the subscription and all the subscriptions are gone!

The data are not lost it is still in your form, but it will not show as you have replaced the fields that are associated with your submissions. You can retrieve this by reverting your form to an earlier version where all submissions were still there.

Please check this guide http://www.jotform.com/blog/95-Introducing-Form-Revisions-Never-Lose-Your-Work-Again-.