Why is my battery charge weakening as well as my fast charger?

Ive had this phone since I’ve turned 20 over two years ago. Last year, while moving large things at my old workplace; my dumbass managed to break the ENTIRE audio jack into my phone 14 to 16 months ago. No standard youtube video at that point could help me.

If thats not enough my battery itself began weakening. I didn’t get a waft or anything, so I assumed the charger port and battery are both at fault here. The youtube videos from this site have made pretty valid points since most of what I was experiencing isn’t what the phone device care system says i was. That i had several intensive apps burning the battery. Usually i have 2 games up but I’m no dunce. So I’ve assumed that the battery is passed its expiration or something.

Another question is there a way we can buy the seal used for the galaxy s9+ on this site