I agree that Antibiotics are the most common factor. However, I've taken Abx at least 30 times throughout my life and didn't get a fungal infection (until last May).
With me, I think it was a perfect storm of all of the things you mention above, plus a prolonged and unusual emotional/stress component.
I'm also struck by how many young people are starting to get this and similar problems after very little professed Abx exposure.
I wonder if the quality of Flora being handed down from mother to child is diminishing in quality/diversity so that it will take less an less disruption of flora to cause problems in future generations. We're in approximately the fourth generation now since Antibiotics were introduced in 1947. It seems that every day we're hearing about new ailments that involve immune system malfuntioning, from autoimmune, to autism to morgellons.