Controller's completely tripping out

I had left my controller to charge, and it was doing so completely fine, some time later I went to turn it on and at first it wouldn't work at all. I plugged it in again and realized — battery's dead. It wouldn't work unless it was plugged in, no matter how long I left it to charge.

But that wasn't the end of the problem. Then, the tripping out started. It started flashing red, green, white, all random, I wouldn't assume it's of any significance. When it wasn't, you could see a dim light coming from it, either orange or green. It only stops when I press the little button under the left trigger, as soon as I let go of it, it comes back. Later on, it started to think it's charging when it's not plugged in, the orange light starts blinking soon after I unplug it and the console seems to think so as well.

I've never had it do something like this, it had worked completely fine before. I'm genuinely confused, and I can't seem to find anyone having the same issue as me, I'd assume a battery change would fix a part of the problem but at the same time I'm hoping it's some glitch in the software that can still be fixed without wasting money. I'm hoping I can get some help with this.