How to access my library from another country

My kids smashed my computer and my ipod. I have a huge itunes library but haven't bought anything new since they did this in 2011. I am visiting a friend in the UK. I have bought an ipod here and want my stuff back on it. I can access my account but not my library on their MAC computer. Is there anyway of doing this? I read that authorizing a computer will only access you into your account, not the library, but surely I must be able to get into my library without having to buy a new computer back in the States? Is this something I can use the icloud for?