I think this is a loaded question, as it contains a controversial assumption. I don't agree with what you say that an attraction or love is the opposite of phobia.
As you yourself properly noted, phobia is a fear of something. The opposite of being afraid of something is being brave towards it, which is defined as bravery or courageousness, which in my opinion both are proper antonyms of phobia.
Now whether courage is rational or not is very difficult to distinguish and it raises a few philosophical questions, which aren't fit for this place, but all in all it's safe to assume that if the following is true:
The man who entered the building on fire and rescued the unconscious woman must have been extremely brave!
Then bravery is irrational, as going toward fire (danger) is not rational at all. It can be considered stupid, irrational decision and if one did that trying to save someone, but dying instead, their actions could easily be considered stupid, irrational.
Therefore I believe it's safe to say that an antonym of phobia is courage.