There are many ways to unblock blocked sites, I do it in my university all the time. You can Use web proxies,Use VPN connections, Hide IP software , translation services like google translate(post link of the blocked website in the translation field and choose a random language to translate from because translation from English to English is not supported.), Use Google cache, use Wayback Machine(wayback machines literally takes you back in time of a particular website but has recent pages to, for example 2 days old pages), Use Web2Mail service( free email service that can sent to your email address specific web pages),change the http of an URL into https(does not work most of the time but for some sites does), use IP address of the website instead of URL(cmd ping domain.com to find out the ip , this does not work everytime as well).
My apologies I didn't cover any option in detail but I hope this helps.And if you need to know more about any of this , ask.
Permanent solutions might not be feasible options for you but you can:
1. Call your ISP and ask them to unblock the blocked sites.
2. Invest in a good paid VPN (can be expensive, the free ones are garbage).
3. Change ISP.
Just a thought . Could it be a naughty sibling messing with your computer? there are some free parental control software which run in the background(invisible) that can block the websites specified( I suspect this because from the sound of your OP , all of your favorite sites are getting blocked). Another way is to do it for browsers specifically by opening host file from C:/Windows/System32/drivers/etc in a notepad , locate the line "127.0.0.1 localhost" or "::1 localhost." and append the site name than save file. A couple of other ways too. Do you have naughty siblings,cousins etc in your house these days?
Most of what you listed here was nonsense. All the op had to do was check if the sites worked in other browsers (hence eliminating that it was merely a browser issue) and if it wasn't, ping the website address. You listed a bunch of things that weren't even relevant to the problem. I gave you some negative feedback in relation to that, and you brought up rants first, again, when it wasn't even relevant.
Then, WHINY CUNT had to get involved when I wasn't even addressing him, I was talking to you. I don't even have a problem with him in this section, because unlike yourself he seems to know what he's talking about.