My phone's Battery performs like a 4000 mah battery but it has 7000. Battery drains quickly. In sleep mode also it consumes Battery more. I don't know what to do. I don't play games still it gives less back up

After using 5 to 6 months battery drains rapidly. I have 7000mah battery but it hardly gives a full day back up with normal usage.

When I bought samsung f62 selfie camera was good. After using 6 months it now takes low quality photos in selfie as compared to when bought. Selfie becomes whitish in daylight most of the times... Rear camera is good