Heavy head and diziness. Nothing found.

I have been feeling dizzy and heavy headed frm past couple of months. I visited neurologist and he diagnosed it as Migraine associated Vertigo. He asked me to take Amitone 25 and Stalopam . I tried them for 2 weeks but no joy. One of my friend suggested me to use Vertin 25 and Stemitil. It worked and I was feeling better. Now after a week I have again started getting this vertigo attacks . I have tried the medicines but no joy. One thing I have observed is I get this attacks when I am in AC environment ( Car or office) feel better at home or in open space. My ear are blocked and have heavy headed feeling which lasts for more than 24 hours. I feel better when I sleep but it starts again when I wake up. There have been times when I felt like I am going to pass out. Need help. Been to 4 different docs .Did CT scan, neck xray, MRV scans but nothing found.