Did u make backup first? Contacts exported on sd? If answer is "yes", Go to recovery now. Go to Wipe menu,then click: "Wipe all data/factory reset", then click "Wipe cache", then "Wipe dalvik-cache". Now go to prevoius menu, click on "Flash zip from sdcard". Uncheck "Signature verification". Try to instal zip again. I did like that and it worked.
It's possible that 1.5Gb of ext4 is to large. Make 1gb.