Thanks for writing your query.
After reading your post, I would advice you that you should first have a scan of your head done.
MRI of head and neck will be beneficial to know the cause of your symptoms.
Also get a clinical examination by an ENT specialist
and a Neurophysician.
You can take Betahistine
16 mg thrice a day for dizziness
Pain killer like Ibuprofen
one tablet twice a day after meals will help in relief of pain.
Continue taking Lansoprozole. You can add Domperidone
10 mg for nausea along with it.
You should first get yourself clinically examined and take any medicine under medical supervision only.
I hope this is helpful to you.