Phone won't charge/turn on

About 2-3 days ago, my battery began to drain really fast, and charged very slowly. My phone use didn't change at all before this. I tried different chargers, outlets, soft reset, I got apps to clean my phone, nothing has helped yet. As of this morning, it no longer turns on. I searched online and tried to clean the charging port, but that hasn't helped either. It's plugged in to a charger right now, and while the charging light is on (and has be on for about an hour) it won't turn on.

Should I try to replace the battery or do I just give up and buy a new phone.