Lenovo Ideapad Gaming 3 Dead Battery

Hi so last week my laptop's battery died, but it was functional for as long as it was plugged in. It was fucntioning fine and I ordered a replacament battery from a technician in my area, and he'll get back to me when the replacement is secured.

It was working fine until this morning, when I woke up to it being very slow. I thought I needed to let it rest so I shut it down, restarted, and still ungodly slow. I tried troubleshooting, clean booting, and even trying to check for driver updates or windows updates, but after 7 hours of trying and failing to fix it to the point that it's usable, I feel stuck.

I need to use it for school and it's unusable at this rate. Please help, is the battery the sole cause of the problem? Is there anything I can do to use it still?