And I haven't got a clue why 
.
For context, I am only 29 and whilst I went through a short phase of brushing my teeth way too hard as a teenager when I had braces, I do not brush hard now nor have I done so for years.
Do I need to see a dentist now or can it wait? I was planning on waiting as I didn't think it was urgent but of course I have only gone and scared myself by Googling it and apparently if they are left untreated then they'll probably just receded further and my teeth will fall out...