Constantly freezing

[Ruled]

Yesterday I was in the middle of watching a tv show and my pc just started freezing out of nowhere. It freezes every around 3 seconds for from 1-20 seconds depending on what I am doing. I have no idea why and I've had this computer for around a year now and have had no trouble whatsoever. To give you an idea of how bad it is it took me about 10 minutes to sign in. It takes me about 10 second for my computer to get from pressing the on button to getting to the home screen but once i reach the home screen it takes like 3 minutes for things like skype and google to come up (Prior to yesterday it took around 10-20 seconds).  Can anyone give me a possibility as to what it is?

Also, I don't think it was the streaming site as I've used the site for like a year now and it has given me no trouble. (watchseries.cr)

Thanks in advance for any replies.