How do I get back to a question that I now wish to edit?
Please see below.
One - It is assumed that you are editing a question answered by yourself. In such a case, when you open your profile, you get a list of all the questions answered /edited by you. If it is not there, just click Show more activity to find the same. Once you get the question to be edited, just click it and you get Edit, Share, More against your name (actually against the name-id of person answering the question), Click edit to make changes.
Two - If the question to be edited was asked/answered long back, one needs to search for it in search bar at the right hand top. But this may throw up large number of questions and finding the right one may be tedious.
Three - One can also decide to edit a question at a later stage, particularly if it requires lot of formatting / adding graphs / images etc. For this open a question and just below it you will find a star clicking which you can choose options like Favorite, Answer Later, Edit Later etc. Choose "Edit Later" and you can get back to it for editing later. These are now available under My Collections.
Four - In case you want to edit a question for its subject (or a topic within a subject) , minor correction or want to report it, that too can be done by opening the question and clicking Edit Question.