Battery issues - glitching

So, I have an iPhone 11. It’s not a pro max, if those specifics matter.

I’ve had some pretty big issues with the phone as of late, such as it getting hot very fast, which I am equipped to handle, but now a new problem has surfaced.

My battery percentage has been glitching. It started when it got to around 80%. It was stuck at 81 for a while, until I let it cool down. But the problem wasn’t just the percentage being stuck at 81. I restarted and also rebooted (held down the volume and home / siri button - then just the home / siri button until it showed the apple logo) the phone a few times when it showed no signs of the battery problem being fixed.

Each time it restarted / rebooted, the battery was on a different percentage. 81, 84, 85, etc.

Like I said, after, it was working properly, and then stopped again out of nowhere. Same scenario again, this time in the 90s percentages. Stuck, restart and reboot a few times, different percentages, working again.

And I’m aware that that can happen when the battery becomes too warm, but the problem is, the battery actually wasn’t that warm, if at all, really.

Now I’m wondering what’s going on. It may also be iOS 14, as I’ve heard some battery complaints about it, but I don’t want to assume it’s just this or that.

I’m also aware that rebooting it can cause it to glitch, and you shouldn’t do it often, but, again, this was happening before the reboots and with simple restarts.

Of course, I am also aware that it may be the battery, but I really don’t have the money as of right now with the pandemic going on to get the battery replaced, and I’m really hoping someone can tell me I’m not alone here and that it might not need a whole new battery. But if that’s what the case is, it is what it is.