I do not understand what you mean by "I then transferred them over to my 'The Questions in this Quiz' ". Do you mean (a) that in the Editing Quiz page you clicked on the "Add to Quiz" icon to put your questions into a Quiz? Or do you mean (b) you transfered your questions into a different questions category? Let's suppose you mean (a).
When you "stupidly" deleted those questions, you must have seen the following warning notice:
Are you absolutely sure you want to delete the following questions?
* question #01 / * another question / * etc.
(* Questions marked by an asterisk are already in use in some quizzes. These question will not be deleted from these quizzes but only from the category list.)
Here is the procedure to restore questions which are still present in a quiz but have been deleted from the questions bank. In the questions bank, check "Also show old questions". Then check each question you want to restore... Note that unfortunately deleted questions have to be restored one by one, there is no "restore all" feature. See attached screenshot.