The official definition is:
The biological half-life of a substance is the time it takes for a substance (drug, radioactive nuclide, or other) to lose half of its pharmacologic, physiologic, or radiologic activity
So yes, the dose you take today, will be reduced in half after about a week. However, the effectiveness of today's dose will not be realized for about 6 weeks. It is also a cumulative effect.
An option instead of waiting 6 weeks to improve would be to skip a couple of doses to get the level down quicker. You might ask your doctor if this is a good idea.
By half-life do you mean that the effectiveness of one dose of the medication last 6 days?
The half life is about 6 days. It will be out of your system in 5-6 weeks.