is a very troublesome problem and i understand your frustration regarding the counts not improving despite taking all medications.
I believe there is some other factor interfering with normal production of sperms in your reproductive system this can be something as simple as waering very tight underwear to stress to radiation
exposure at work, exposure to harmful chemicals,fumes at work or otherwise, smoking, alcoholism
some surgical conditions like varicocele
and so on.
The treament essentially depends on what is causing the decreasing sperm count
If you havent been evaluated for all these i recommend you do so in consultation with any general physician at your place.
Dont lose hope.