I’ve always had the temperament for it and my mom would withhold love if I didn’t do something right while I was growing up. I got bullied all through school for not being normal. It was around age 14 that I started with depression and an eating disorder but looking back I can see lots of my bpd traits from at least that age. I had a lot of risky sex as a teenager, drank too much, started cutting, would often get in fits of absolute rage, etc. I didn’t get officially diagnosed as bpd until I was 31. I struggled all those years with treatments that didn’t work (and still am struggling with this today) but now I know why.