What texting app do you use and do you use the Samsung keyboard? I use AccuBattery for my battery status but you can get screen on time by using the Samsung Device Maintenance app.
My battery starts to drain before I even leave the house in the morning. I charge it to 100%, takes me about 45 to get ready and about 15 mins to get to work. Before I leave the house, it's down to 96% and when I get to work it's around 95% before even using my phone. I stream a show using Podcast Addict at work and I get a great signal at work. Right now, I have been on battery for 7 hours 53 mins and I am down to 52%. Kind of frustrating.