Your wifi adapter brand, Nineplus,(full name Shenzhenshi jiujiadianzishangwuyouxiangongsi) sells wifi for as low as $11 USD. Generally, when you see something like that, quality isn't the first thing that comes to mind.
My first suggestion would be to get a better wifi adapter, suck as a Tplink or an Asus, and see if your situation improves.