iPhone can't connect to internet sharing

At my university I only get internet access via ethernet. 3G coverage is dreadful where I live, so I want to connect my iPhone and iPad to the internet through Internet Sharing.

This used to work intermittently, I'd have to turn Internet Sharing off and on again for my phone to connect. Now, even that doesn't work. I get the internet sharing icon (the up arrow) on my computer and my phone can find the network.

However, when I try to connect, the spinning wheel keeps spinning and it won't connect, the wifi symbol doesn't appear in the top-left of my phone's screen.

I thought it might be the firewall, so I switched that off. I changed my network name and tried several different channels, but nothing works.

If someone can help me with this that'd be wonderful, this is hugely inconvenient for me.

These are my settings, I also tried not using a password by the way.

This is what I see on my iPhone. The thing keeps turning and nothing changes. It's the exact same story with my iPad.

Please please help, thank you.