try running some terminal commands out of the filemaker server guide. This one always helped me:
FMSADMIN RESTART ADMINSERVER
Also, did you update java yourself? Or did you let FMS install the version it likes during it's own process.
After FMS 13 became non responsive I decided to uninstall and reinstall.
really worries me to hear. an uninstall and reinstall is not something to do on a whim or take lightly, it should be an absolute last resort.