Copy the state of controls and variables from one Form to another in c#

I have a windows form. If the user doesn't select a checkbox, a new form opens later when they press next, but if they do select it, the same form is used.
I want a clone of the current form to appear (with the same variable and control values) if they select the checkbox, so that they can change values later without deselecting the checkbox, and pressing next again, and typing in the other values manually.

Form duplicate = this; just references the same form and there is no such thing as new(this).
I couldn't try Form duplicate = new Form() = this as my form takes constructors from an earlier form

Anyone knows how to do this? Thanks in advance