I have been taking tamiflu for the last 4 days but now i have an incessant dry cough that just doesnt let up. not very productive but cant sleep well?

Doesn't seem serious: This does not appear to be serious. In fact, this is likely an expected symptom of a resolving flu-like illness. This apparently started very recently, and is your body's way of clearing mucus out of your chest. It should resolve in a few days, but if it gives you too much discomfort, some simple cough medicine should help. You could also see your Dr. if it is still an issue. Good Luck.