iPhone Pro Keeps overheating/dying IOS 26

I bought my 12 Pro on Launch and told myself I would noit upgrade unless the phone DIED. I replaced the battery last summer and it's at 89% and it felt brand new one I did that. I was on IOS 18 though when all that hacking information came out so I decided to update to 26 two months ago.

Ever since I pudated my phone, it overheats after maybe ten mins of use, and it's always dying under a hour, it's gotten to the point where I just don't even use my phone if I leave the house because it'll just die.

Should I just get a 17 or wait until the 18 whenever that drops? Or does someone know how to fix this overheating/battery issue.