Battery more drain and phone is heating up

You are not speaking with Apple here. This is a user to user support forum and Apple does not participate here. If the battery is draining more, and it is heating up, your best bet at this point is to check Settings>Battery>and then check the Activity section to see what app or apps are using the highest percentage of battery and work on your troubleshooting from there. After checking the first time, then to a force restart on the iPhone. See this for those instructions and see if between the two different recommendations if the battery usage changes. Also, what is the current Battery Health on the device?

You need a battery replacement. See this for getting this done. Apple Support