I Take Warfarin Daily To Thin My Blood, I Had

I take warfarin daily to thin my blood, i had heart surgery and got a metal valve (top hat) placed in. Lately been having trouble keeping my inr stable between 2.5-3.5. They keep upping my dosage of warfarin which in turns makes me feel even more sick. Is there anything to soothe the discomfort. Its too a point where i feel completely overwhelmed. If you have any suggestions or help to guide me that would be great.