So i have a iphone 6s which is 3 years old. I have taken care of it up until recently. 2 month ago i dropped it the wrong way (glass didnt shatter or anything) but the screen went completely black but i could still get phone calls. I spent about $90 replacing my screen. Now my battery health is 73% and its getting really bad and annoying because i always have to keep it on the charger (I am so done with charging cases). A battery replacement is like $55 where I live. What should I do?