An Air Force veteran who agreed to testify before Congress about secret government UFO programs died just months before the hearings of an accidental drug overdose, The Post has learned. Matthew James Sullivan, 39, died at his home in Falls Church, Va., on May 12, 2024 from a lethal mix of alcohol, alprazolam, cyclobenzaprine and imipramine, according to the Northern District Office of the Chief Medical Examiner. Alprazolam is generic Xanax, an anti-anxiety medication; cyclobenzaprine is a powerful prescription muscle relaxant that works on the central nervous system; imipramine is a drug for children used to treat anxiety and bedwetting. Former Air Force Intelligence Officer, Bronze Star recipient, and critical UFO witness Matthew Sullivan died from accidental drug intoxication just weeks after he agreed to testify to Congress. Dignity Memorial The mysterious death is of “grave concern” to Rep.…