Are calls and texts working? If so then check your internet settings and if the APN field has changed from 48months.liffeytelecom.com then edit it to change it back to that, reboot and see if data works. If it doesn't then you'll have to contact 48 support. See the link in my signature below. Unfortunately it seems to be a common problem for some people for data not to work while roaming in the EU on a Guido membership even though this should just work.
Hope this helps.
I am not a 48 employee so if you need to contact 48 support then use option 3 or the chat facility here.