Extremely diverse Internet issues over the last few days

It all started a couple of days ago when my phone (nexus 5, updated to lollipop) would drop the WiFi speed from about 40 mb/s to 0.3 after a few minutes of being connected. After that, my laptop started losing speed too, so I unplugged the router and plugged it back in. Then nothing would connect to the WiFi, on my phone the network would remain saved and on my laptop it would connect but be "limited" with no Internet access. I rebooted the router and nothing. Then it started changing on its own. My pc wouldn't get Internet any more (via ethernet), going to the router's settings page would take me to a blank page or simply wouldn't load, it has periods where the Internet works well but only if I am a inches away from the router, otherwise it doesn't, even if I have full signal. I have no idea what is causing this, first I thought it was my phone, then my router, then my Internet connection.. I am really annoyed and confused. I could really use some help please.