There is a way to do it using AJAX where instead of passing the variables to another page, the variables are passed to the same page and the content changes via if else statements.
The link is: https://trevordavis.net/blog/tutorial/wordpress-jquery-contact-form-without-a-plugin/
If you want the variable to be echoed you might have to modify the code a bit since it has been created to handle contact forms.
If anybody else knows how or if it is possible to pass variables from forms to the action page, please let me know as well. I have been searching high and low for it and have yet to find an answer.
