Had positional vertigo for over 10 years. Hallpike positive, but after treatment, it comes back mildly usually after I get a cold. Vestibular neuritis?

Good case. A cold can make symptoms worse, for sure, but I do not believe that means it is vestibular neuritis. Since you are sensitive to the Hallpike and you feel better with positional treatment, it cannot be just a case of vestibular neuritis. There must be a benign positional component too.