have u installed your previous backup on this ROM....?
if not.. then try to wipe your all data / cache... problem will resolve..
i have done same thing when i was facing this issue..
now no problems at all
go to wipe your data by going recovery mode
by log press of power button
now select recovery..
then in recovery mode.. wipe data/cache
this will make your ROM on first stage when you installed this ROM
and start from 1st point..but this time.. make sure you have installed low RAM usage apps