I have been taking Warfarin for 3 months after an Infarct Kidney....

I have been taking Warfarin for 3 months after an Infarct Kidney. (blood clot in my kidney) was ordered to start taking Warfarin, within a week I started getting a very dry mouth like as if you would get after a good night of drinking! After about 2 months the dry mouth started to go away and is only slightly bothersome, however, now I am experiencing a light headed and a dizziness feeling, not to the point where I am gonna pass out, but very uncomfortable. I have a hard time concentrating, when I turn my head quickly to look or because I hear something is when I will experience a quick rush of dizziness. I have been taking about 7-9 mg per day depending on my INR level. Anyone have any ideas that could help me with this?