Issue after lollipop recent update

Hi! I updated my handset to latest ota and now the phone seems to be unusable. It restarts on its own, cant even make or receive calls. It keeps restarting everytime. Lags too much. Can someone help y this is happening? I have too much data so wud prefer not to flash as it will wipe everything. Pls help

Sent from my VS980 4G using Tapatalk