Is my Battery/MacBook Pro shot?

Hey all. This is kind of a long one, I apologize for that. So lately, I've been noticing this VERY loud whirring/grinding noise and the laptop gets very hot all while doing seemingly basic tasks like listening to iTunes or browsing the internet. So this morning I decided to open up the cover and clean out the fan. I didn't use compressed air or a vacuum, just a q-tip to dust the place out a little bit. Before dusting, I removed the battery for safety concerns and, but before that, the butt of my screwdriver touched the logic board on those white, grain-of-rice-looking things directly below the connector for the battery, and it sparked (the pics are of the logic board after the sparks). The butt of the metal screwdriver had a scorch mark, but as you can see, the logic board appears unaffected. I felt nothing when it happened. After dusting, I reconnected the battery cable and secured the battery back in place with its screws and put the cover back on. I restarted the computer to see if the problem was fixed.

It wasn't. I tried turning it on but nothing happened. Then I connected it to a wall charger and it turned back on normally, though the sound and heat were very much still in effect. The computer started, very slowly, although it never is quick, and i tried disconnecting the charger. The screen immediately went black and the entire machine shut down a few seconds later. I restarted it with the charger attached and I noticed this time (this was the first time I noticed it, but that's not to say it didn't occur on the initial restart after closing the cover) an x inside an empty battery where the battery icon is. There is no percentage even though I have it enabled, and this is the first time I've ever seen this. When I click on it, "No Battery Available" and "Power Source: Power Adapter" are grayed out. When I go to System Report this is what I get for Power:

I have tried restarting the machine, an SMC reset, I've tried removing the battery, blowing on the connectors, and then plugging in the battery again (I have tried this several times), and nothing has yielded a different result. The battery connector was taken out with a plastic prying tool and all parts, including the battery, were set on a bed when they weren't in a computer. They were in no contact with any known magnets or static fields and they did not take any blows.

What's happening?? All parts of this MacBook are Apple made, but it is pretty old--2011, I think. This theory may be laughable, but it's literally all I have to explain this: The battery needed replaced to begin with, even though it was working perfectly fine, and disconnecting it somehow pushed it over the edge into not working. I have no idea why this would happen because I have 0 technical experience, but that's all I got haha. Thanks!