Why is my phone won't turn on after several hours of charging?

Hey! So, yesterday, all of the sudden my phone died down and showed this red battery and charger logo. So, I charged it and it showed me only the red battery logo. I left it for one or two hours. When I came back, it still showed a red battery logo when I try to turn it on, so I decided to leave it overnight.

The next morning (today), my phone shows a completely black screen. Nothing that I do (home+power button method, heat it with hairdryer method, and my iTunes doesn't recognise it when I plugged it in) change a thing to it. For several occasion, my phone responds and shows the red battery with the charger logo again, so right now I'm just charging it but it still doing nothing and only shows the black screen.

What do you guys think I should do? Is the battery the problem? I'm planning to change it to a new one because my battery keeps draining so quickly, but do you think it's something else that is causing this problem? Thanks