Error 552: Insufficient storage space available during startup KB18751-Error "Reload Software: 552" is displayed on the BlackBerry smartphone
If it will boot, then you need to delete at least the last 2 or 3 apps, themes, songs, etc. that you installed. You can also try connecting with BBSAK.
If it will not reboot, you will need to wipe the device with Jl_cmdr (see the FAQ) and then reload the OS (see the sticky at the top of the 8300 section for the latest 8330 OS and the instructions.
I hope you have your data backed up, otherwise, it is gone.