All sent forms auto change when I change any of my contracts to Tailor fit the event.

I do photography and have different packages.  However I have one form for portraits that I use.  When I make changes to my saved form to tailor fit the session for example, a boudoir vs family session, it changes all the details in every form Ive ever sent, even if its already been signed by a client.

So: When I sent the form to a client for a family session then later that day sent another for a boudoir session.  that family session now sees "boudoir" instead of "family" 

Is this fixable? Do I need to re create a new form for every submission?

I am not sure if I have understood your question correctly. What changes you make in form?

Please note that if you edit form and then edit the previous submissions, the changes made to form will be displayed in previous submissions as well. I would suggest you to please explain your issue a bit more in detail and we will try to help you.

I would also suggest you to please share a screenshot of the issue as well before making the changes in form and how it reflects in the previous submission. The following guide should help you how to upload image in forum post:  https://www.jotform.com/help/438-How-to-Post-Screenshots-to-Our-Support-Forum

We will wait for your response.