I am just guessing here but I suspect that your CPU is overheating because of accumulated dust and debris on the CPU heatsink. This is not an unknown problem on that particular model.

Suggest you buy a can of compressed air and use it to thoroughly blow out the vents in order to dislodge as much dust and debris as possible from the heatsink without actually having to open the laptop.

It may also be prudent to run the Dell diagnostics in order to eliminate a faulty CPU heatsink fan.

Alright, the computer won't even start up anymore; the charging indicator doesn't come on when the computer plugs in, and when I press the power button, the lights come on, but only for a couple of seconds. I tried taking the battery out and plugging it in that way, but it doesn't help. I also tried taking the RAM out, and it didn't help either. Any other suggestions?