Left AirPod sounds weaker

I’ve repaired it to my phone cleaned it and did a reset but I still can’t hear very well out of my left AirPod it gets weaker and I have to have my right one in most of the time and I originally got these from my mom On Christmas 2019 and they worked perfectly now the left one sounds like crap and I have to have the volume on like 30-40 percent what can I do to repair it Without damaging it more and not spending to much because I’m only 13 thank you