iOS15.6 BUGS

After installing 15.6 (I was having enough issues before this) Im having more issues than I should.

• phone won’t charge properly & when it is properly charged it doesn’t last half a day
• I’ve only had this phone for a year max & my battery health is around 80s%
• DANGEROUSLY OVERHEATING! I actually burnt myself the other day & got a blister from it. My iPhone Max the battery exploded. I tend to keep a case on iPhone 12mini like heavy duty otter box & I know it probably isn’t helping I have that small fan area covered. It got a bit better after taking it off but I’m not gonna risk taking it caseless. & even though that helped keep it cool it still burns me once in a while. This scares me for many reasons first being I have small children who like bringing mommy her phone & could get hurt second being I don’t want the battery exploding or a fire starting. Two problems too many & that’s just for starters I have many more
• has been much more sensitive to touch (I think I can handle that with settings)
• have had to delete a ton of photos & apps because it keeps saying storage is full which is bs because I didn’t have the problem prior updates. Not only do I have regular frustration saying full storage I also have iOS @ 8.6GB & system data is almost 14GB.

Any suggestions?

I can try & get one of the ridiculously out priced flash drive looking things, save everything to it then get everything off my phone. I’ve cleared the cache removed specific files & documents, put things on the cloud which makes me nervous (too many horror stories for the cloud to handle anything to personal). I do not want a new phone, it’s only a year old & I’m still paying for what I currently have so not an option.