What's the actual problem here? Is it that you can't setup your TV to connect to the network because you're using a new SSID? Just change it back to what you used to have.

Just buy a replacement remote. Most Sony remotes are interchangeable.

Try Android TV Remote or Sony TV & Video SideView

Any chance you can connect the TV via Ethernet to the router? Should let you connect via your phone to then set up the wi-fi?

This appears to be an IR remote. Sony remote codes are pretty consistent so a uni remote should give you most functionality. If you use an Android phone or tablet you might want to try this ap https://play.google.com/store/apps/details?id=com.moletag.galaxy.s4.remote I've used it and it works pretty well.

You mentioned it has a USB port you've tried, perhaps plug in a mouse/keyboard if you have one?