As >>3939, if you want to function in this world you will need internetvon your phone to whatsapp, you need check your email everyday.
I stopped smoking weed by not going to Amsterdam amymore, it's a bit more difficult with the internet/computer.
That being said, I didn't beat this addiction yet but my methods so far are to delete all and any games you have (including minesweeper and co). Next install mozilla add-on leechblock and delete all other browser (if you know something similar oj another browser, go for it. Although in my experience this is the best website blocker). Block all timewasting sites but keep an hour a day open. Also make it so you can't access the add-onn from the outside and disable leechblock.
Then make a new user on your computer and give it administrator rights and take away yours so yoi wkn't change the clock manually to go on the hour you can have your free time.
That's where i'm now, good luck.