I suffered a concussion three months ago. I'm 50 yrs. Have had MRI (negative) and seen multiple neuroloigists. Dizziness/headaches persist now for for three months. Will this ever resolve?

Most likely. Symptoms of concussion may take weeks or months to resolve. Be patient. Check with a specialist. You may need to reduce physical and cognitive exertion until symptoms improve.
Concussion. Not all concussion have positive mri, mild concussion can present with the symptoms u described, and can get better with symptomatic treatment.
Yes. Dr. Levy, i believe your symptoms will get better. I am not an expert in post concussive treatment. I am sure you have great doctors to call upon for expert treatment. Time does help. Three months I am sure seems like a long time however nerves and the brain take a long time to recover from such injury. A negative MRI is reassuring. You should have a visual field test to check your vision health.