Hello! Thank you for contacting JustAnswer.com; I am Russell H., an Expert here at JustAnswer.com, and I will do what I can to answer your question as well as it can be answered.
I suspect that your phone's battery might have become defective. Please tell me your phone's maker name, and model # if possible too, and I will advise you further.
OK. If it is 2 years old, it is out of warranty, and replacement of the rechargeable battery in it would be either a do-it-youself-at-home operation (there are kits for so doing) or a take-it-in-for-repair matter.
Have I answered your question?