What can i take to get rid of a nagging cough due to i believe sinus drainage i have heard that a simple saline spray is good.can i make thus myself?

Salt water washes: Buy one of the squirt bottle kits with the ready-made packets. Buy a gallon or two of distilled water. Use it twice per day. Huge difference!

Yes, can make it at: Home. Use one cup of distilled/filtered water; bring to boil; add one teaspoon salt; mix until dissolved; let cool; use. There r other recipes, some of which add baking soda. Can increase amount proportionally, if needed (i.e. 2 cups water, 2 tsp salt). Replace solution after 3-4 days or if contaminated with dropper tip or spray bottle tip.