I Have Tintinitus, Post Nasal Drip And An Initial Feeling

I have tintinitus, post nasal drip and an initial feeling of falling when I lie down or get up. I left very unsteady when Getting up after watching a movie in a theatre. This is the only time I have felt unsteady when getting up from a sitting position. This sensation of falling upon lying down and rising has been occurring for a week. I have had ringing in my ears for over 1 year.