So many problems after update to lolipop 5.1.1

[Martnz]

Last week I update my, xperia z2 from kitkat 4.4.2 to lolipop 5.1.1 and after that iam facing serious problems.
1: i cannot record video from my camera.
2: youtube cannot play videos.
3: gps not starting.
I even repaired my phone with pc companion. But it worked for some time only the again same problems iam facing..
Please help what shold i do..iam fed up with this.

[Phy]

If it work for a while but then it stopped working, its a clear indication that a third party app it's causing this problem, boot on safe mode and see if you experience the same problem.

How to boot on safe mode on Lolipop
1. press and hold the power key
2. once you get the pop up menu 
3. press and hold "power off" 
4. Boot on safe mode should become available

[Bearings]

Mantnz, check your 3rd party apps. On your Menu screen swap left to right, press uninstall and you will see which app does not belong to the original firmware. Start uninstalling the 3rd party apps until you find the rogue app. I have issue with my Music app that lost it sound during playback and found the rogue app this way. 

And don't forget to delete the app from your App Store.