Your battery is damaged.

Using your charging brick with this battery will result in it's demise soon. Check the voltage of the charging brick, if low then replace.

Using the laptop in this condition can result in damage to the charging section on the motherboard.

Battery replacement requires teardown of the laptop.

1 Replace battery
2 Replace charging brick
3 Repaste the CPU and GPU while you are inside the laptop
4. Good time to also add more memory and/or storage

If you don't feel comfortable opening your laptop and making repairs (see many videos online about teardown of this laptop) please take it to a service center.

Good Luck