My iPhone 6 camera's quality isn't the same?

Recently the quality on my phone's camera looks bad. This only happens when it's a little dark and I take pictures with the flash on. It makes the picture look kind of blurry or fuzzy. Do I have to replace my camera or what can I do? I've tried cleaning the lens but that's not the problem.

It tries its darnest to make the picture come out right but as far as its abilities can go, it can only be as good as you then there's the new-age problem of taking pictures with a phone but that's a generation thing I guess.