I have a hard time completling sentences, and memory problems. is this permanant brain damage?

Evaluation: A more thorough examination of these complaints is needed. A doctor can do that evaluation wherein he looks into the history, onset, and progression of the problem. He also will look into possible underlying causes. It is hard to give a definite answer based on limited information and without face to face thorough evaluation. Please see a doctor, good luck and feel better.

Unlikely: Some anxiety disorders, especially social anxiety can make it difficult to complete sentences in conversation or while lecturing. These symptoms are referred to as thought derailment or thought blocking. Other psych conditions can cause this as well. You should see a neuropsychologist and a neurologist if there is any history of head trauma , encephalitis or meningitis. Otherwise see a psychiatris.

Neuropsych Assessmnt: If you've had some brain injury, i would imagine you've seen a neurologist. For a fine-grained assessment of language and memory problems, consider finding a skilled clinical neuropsychologist for an assessment. Clinical neuropsychologists work closely with neurologists.