Oh, I have had this problem too! Its your computer most likely being slow since you downloaded all them updates. Use up too 2 browsers don't have any more installed since you may make your computer slow down. And delete your old versions of the browsers so that will speed up the new one. Also make sure you have the latest JAVA, I think its Java 8 now but correct me if I am wrong.
Someone may also have set the limitations on your device small so you only get a very small bit of the bandwidth and the whole house gets the rest of it. Check your internet properties for that.
EDIT: Someone may just be d-dosing you. Most likely not going to happen but if you gave out your IP recently, to someone.... Then you may be getting d-dossed.
He said it happens on his phone too so the browser wouldn't affect other devices, also bandwidth very unlikely to be configured on both devices.