***NEED HELP*** WIFI SINGAL and CAMERA freeze

Hello all, I got this weird problem after the update of my device from Ios 7 to 8.

I. Wifi signal: Wifi signal is very poor. I barely get good signal within a room where modem is set.

II. Camera: Rear camera gets to open, i can see the subject in screen, but when i try to move the device to take some other, the screen freezes for seconds and then gets normal again. Focusing doesn't work.

So worried 😐 Couldn't take pictures when needed the most.

PS: This all happened only after the update, before that it was working fine. My warranty period is over.

Please do help me.

Thanks.