Query to find issues that was assigned to me

Not sure what version you are running or when this feature was implemented but in the filter list which is the first option when creating a query you can now select History (by value) so:

You might try histval[assigned user] = 'me'   assuming you're items use the assigned user field.  This should show you all items where you were an assigned user at some point in the past.  Now the challenge perhaps is finding out when you were assigned which would require parsing the history of the item.