You can try a reset on your device. Hold the sleep/wake and home buttons together until you see the Apple logo and then release. The phone should reboot. See if that helps. A restore from backup is next, and if necessary a restore as new. Both restores will update the iOS. If it is necessary to do the restore as new, that will delete all content from the device, so make sure you have everything backed up, pictures imported and other data synced to supported applications on the computer or iCloud.