If your neighbor was able to reach eBay, that would seem to indicate that the problem was likely at your end or with your network rather than at eBay's end.
Some general suggestions for users experiencing problems reaching eBay:
Make sure you are going to ebay.com and following links from there, rather than relying on old bookmarks. Try using the Site Map link at the bottom of the page for links to most eBay pages.
Try another browser to rule out browser issues, possibly by installing a new one you have never used before. If you are using Firefox, try disabling Enhanced Tracking Protection on eBay using the shield icon to the left of the page address. Try temporarily disabling ad blockers or script blockers. Make sure you have a recent browser version that is up to date.
https://www.whatismybrowser.com/
Try another computer or device to rule out computer issues, if possible. Check to see if your system is waiting to install any updates. Reboot if necessary to complete installation.
Try another network to rule out network issues, such as using your phone or laptop when not connected to your usual WiFi. If you are using a VPN or custom firewall, try disabling that. Some UK customers have recently had problems with Service Providers' Child Safe settings preventing eBay formatting from loading properly.
If you can reach other sites but not eBay, check downdetector.com or similar sites to see if eBay is experiencing more problems than usual:
https://downdetector.com/status/ebay/
