What does it mean if I have aphasia?

Not sure what you. Mean, aphasia means trouble using or understanding language, if you are asking about the cause, it is a problem in the brain from a number of possible causes like alcohol or stroke.
Aphasia. "lost for words" is general meaning. Could relate to some neurologic problems or medications. There are several types of aphasia. Best resource is neurologist who can diagnose types.
Traditionally. Aphasia refers to the loss of language function due to brain injury or disease. There are many types of Aphasia, all have in common dysnomia (impaired ability to name things) Posterior aphasias (Transcortical Sensory and Wernike's) produces fluent speech that lacks nouns and verbs with lost ability to comprehend. Brochas and Transortical motor speech affect output- non-fluent sparse speech.