Q: home & lock screen usage 42%

Did you check which apps used the other 52 percent?

All the apps mentioned in that statistic will have to add up to 100% again in the end. So, every time you bring up the home screen, this will be registered as "use of the lock screen", no matter which apps you start after that, counting these events for the last 24 hours.

In your case, for example, using one or two apps after bringing up the lock screen can lead to that result.

Use Notifications on your iPhone, iPad, and iPod touch - Apple Support

I would check to see what apps would be waking your iPhone's lock screen while you are sleeping. Any app notifications to state you have an email, something from a game, text message, etc which informs you by lighting up your screen will be responsible for your home & lock screen use.

Beyond that, you can also enable Do Not Disturb in Settings on your iPhone during the hours that you sleep so your alerts do not wake the screen.

Those details should help to make this issue less so.

When referring to battery life, Home & Lock screen typically indicates that within the settings auto-brightness is enabled, or potentially the screen's brightness is at 100%.

The the brighter the screen, the more battery life will be consumed.

DIsable auto brightness & adjust screen brightness to a comfortable level near 50% brightness.