Discuss with your physician alternative anti-coagulant treatments. Warfaran represents the "standard of care", however there are alternate protocols that provide anti-coagulant action with less risk and side effects. You have to bring this mup with your physician. Check out the national database pubmed, which evaluates many alternatives, including simple aspirin.
Only the result of your INR test can tell you whether the dose is too high or not high enough. INR is more stable for some individuals than it is for others. I hope you are spacing your two low-dosage days at the beginning and middle of the week and that you are not taking a low dose two days in a row and then the higher dose five days in a row. I would question why anyone would need to take warfarin more than once a day.