A phobia is a fear. For instance, I am agoraphobic, sometimes resulting in a panic attack. It happens and I recognize it as a fear-based reaction.
I suppose this is why I have issues with the words transphobia or homophobia (funny, spell check says homophobia is a word, but not transphobia...make of that what you will). They do not get to the heart of what they are intended to address, which is something more akin to a hatred or disgust often revealed through speech or actions. A transphobe or a homophobe (again, one clears spell check...guess which) would be someone with a fear of trans or gay people, perhaps a fear that they will accidentally sleep with one of us? A fear of waking up one morning gay or trans?
The horror.