Why do i have only 1.8 gigabytes of space left?

Since i had my 8 gigabyte Ipod Touch 4G, the only problem i ever had was with the internet because we we're with telstra but since the new update for Real Racing 3 it said i didnt have enough space. I deleted 2 of the 3 games that i could fit on there (NFS Hot Pursuit and Nitro Nation Drag Racing). Now i had deleted all my music and photo and have absolutely nothing except Real Racing 3. There is nothing left to delete and it says i only have 1.8 gigabytes of space left. Another 1.8 gigabytes is the size of the still not updated Real Racing 3. If anyone had the same problem and fixed it then can you tell me how to fix it or if i have to get it serviced or something then can someone tell me how to do that or anyone who does free servicing for ipods (got no money because i spent $30 on a brand new trady case for my ipod which in the end broke and anyother $10 on a stylis that has disappeared). Its currently 5.0.1 but im gonna update it back to 6.1.3