Same here. I bought this phone a month ago and it lasts me at least 2 days and minimal usage. Do you disable all background data apps or certain ones like Facebook?
I generally disable the background data most of the time. I don't use Facebook on my phones. I have yet to run across an app that is harmed, or impeded by leaving background data restricted. Besides social media.
I also look at each app. I look at what permissions it has and if they need it. Some really make no sense. Why would a news app need access to my SMS messages or my contacts.
Within each app I will also restrict it from accessing data on 4g, unless I want it to.
Don't get me wrong I use data. I'm over 15gb this month. I just want to use it as I want not as some app thinks it needs it.
I disable or uninstall and bloatware or apps I don't use.
Hope this answers your questions. If not ask away.....glad to help.