iPhone heating and rapid battery health drop

I have a generally new, though older version, iPhone (iPhone 13, to be precise). I find that, unlike other people's iPhones, mine heats up rather fast and degrades my battery health too. I have tried to instill the common practices to care for battery health like not letting the battery drop below 20% and making sure it's not kept in a hot temperature area.

Still, my phone seems to heat up faster than others. Whether I am using Wi-Fi or mobile data, my phone seems to heat up incredibly fast. Within 7 months, my phone's battery health has already dropped from 100% to 93%, and the drop happened over the summer (I live in Asia).

I'm worried that I might need to replace the battery soon, but if the issues persists, what can I do to resolve it? I have quite the number of applications since I need them for university. But I'm starting to think that they're weighing my phone down by a lot.