What can I do to control constant runny nose? Don't think it's allergies because I tested negative.

Nonallergic rhinitis. Your primary care physician or allergist needs to take a comprehensive history of your symptoms. After age 30 or so, nonallergic rhinitis becomes more common. This is easily controlled with ipratropium nasal spray, if one of your doctors thinks this is appropriate for you.
Runny nose. You can still take antihistamines which will still hopefully treat the symptoms even though allergies testing negative. You might want to be evaluated by an ENT and make sure your adenoids aren't playing a role in this story.