iPhone 11 Bugs

I got my iPhone 11 in December of 2019 and since December of this past year (2020), it's performance has gone done greatly.

First, using some specific apps drains the battery quicker and makes the phone heat up entirely. Even when charging and using these apps, the phone will heat up and barely increase in percentage. Also, simply using the phone for everyday use, like opening and switching between apps, is very slow and sometimes makes the phone freeze. This also happens when I pull down on the tab to view battery percentage, brightness, etc.

Overall, phone battery lasts for a very short amount of time, takes over 4 HOURS to charge fully, and has very slow performance. Battery health is at 86% so I shouldn't be experiencing these problems so early on. Any solutions other than changing the battery?

*Attached below is another one of the bugs I've been experiencing frequently.