System Defender Killed my Internet

So last night I had an attack by system defender, and it was a struggle but I believe I was able to remove it using Malwarebytes. However, since then I've been unable to connect to the internet despite me knowing that there is a connection, and I believe its because of system defender. I used spybot and malwarebytes and I'm in the midst of following the "READ & RUN ME FIRST" instructions but thus far I still have no internet (I'm at the school library right now). I believe its because the HTTP port is blocked, and I'm clueless as to how to free it as I've tried various things like changing firewall settings and such. Help is much appreciated thank you.