Dell Inspiron 15 5000 - Charger stutter issues

Hello, I own an Inspiron 15 5000 for about 2 years now and since the first few weeks I have some issues with my charger that have been getting a lot more troublesome lately.

2 years ago, my only problem was my notebook kept shutting off when I plugged the charger in (It only happen every once in a while), it was annoying, but I managed to live with it.

For about a year, my issue got a lot more serious: The light that used to be on (on the front side of the notebook) when I plugged the charger sometimes won't light up anymore, this is only a problem because, I noticed that, if the light is not on, the notebook may still be charging but it gets a huge performance drop... A good example of that is when I'm watching a video on YouTube without the charger: Everything is fine! But when I plug the charger and the performance drops, the video (and audio) starts to stutter and the RAM/CPU usage goes all the way up.

The only workaround I found was plugging in and out the charger until the light stays on.

THINGS TO BE NOTED:
*I use Windows 10, but I'm pretty sure it won't make a difference with another OS.
*I guess it's not a problem with my energy settings, since I already changed it so many times.
*I hope the charger is not the problem, as if it is, it's faulty since I bought it on a Dell store.
*I'm willing to replace the charger, but I would be glad if I could try every alternative possible before replacing it.

Thank you for your attention!