I suffered from intense boredom as a child until Inwas a teenager. I also MADE myself cry at night by thinking about sad things. I dunno why I did it. I just liked it. Are those related to being BPD?
@FlawedGenetics
I'm not quite sure, but I can tell you that I did the same and that wasn't that serious but after with that I created a depressive episode... Even wanting to cause your sadness is a sadness, way to feel relieved. I think it can be related to BPD because of that feeling of boredom, but I'm not quite sure. Such an interesting question.
I was probably around 5-6, in kindergarten when I was feeling different.. like a lot of anxiety, I was feeling different and big which I wasn't and I was very possessive of my best friend. And even at that age it felt strange.
When harming myself became an acceptable mode of behavior, I noticed something was off. So, about the age of fourteen. Before that I had had a preoccupation with all things morbid, abandonment, abuse, and struggled with depression, but didn't have a name for it then. It wasn't until my early twenties that I finally learned how to fight back.
I started withdrawing around 10, and by 11 I knew there was something wrong and it was then I started self harming. But up until I was 16/17 I was 'okay' with just thinking it was depression, anxiety, and PTSD until around 17 when I started showing bpd symptoms and dissociated for the first time. I'm not quite sure when I started showing psychotic symptoms, but it was around 18-19 I think.
In 6th grade, during lunch I asked the vice principal (who supervised our lunch hour) how many calories were in the pizza I had just bought in the cafeteria. I'll never forget the look on her face. She was so confused. At first she thought I was joking but she quickly became concerned when she realized how serious I was.
I didn't know it was different or "wrong" to count calories and restrict what you ate. It's what I'd always done.
I started my first diet in the 4th grade. Still morbidly obese in college...
(tw) Probably whenever I tried falling asleep with a plastic bag over my head when I was 5-8 years old. Or when, in preschool, I chased a guy around the playground until I caught up to him and scratched his back so hard he started bleeding. Or when I always got into fights in Elementary and got kicked out of summer school. Or when I found a diary from 3rd grade detailing all the calories I consumed each day, gradually getting less and less until it was less than 50 a day, and then realizing I'd probably eaten that amount or a little more than that when I was living in my step-father's roach infested house and almost never got a decent meal because he just didn't know how to take care of me. Or when I got drunk with my aunt and one of her friend's called me skinny and I broke down crying. Or whenever I ate 2 bites of celery and immediately ran in the bathroom to purge. Or whenever I started self harming in 6th grade and then tried cutting a few years later only to realize it didn't hurt me nearly as bad as what I was already doing, and then realizing I liked the blood. Or when I got physically nauseous and repulsed whenever I thought of putting anything in my mouth due to past abuse. Or when I spent my whole middle school life day dreaming based off books I'd read to the point where real life felt like some dreary dream itself. Or when I started getting alcohol poisoning and throwing up on a weekly basis during 9th grade to purge myself of all the ugly feelings inside of me. Or when I finally looked back at all this and realized it wasn't normal.
@tranquilVision80
Thank you for such transparency in your sharing. I hope your words reach someone in need to not feel so alone. 
TW: self-harm thoughts
I'm starting to think I have bpd. My parents split up unexpectedly, they both smoke and my dad drinks. My dad smashed all the plates in the house because he was so angry with my mum. He didn't abuse me though. I would always listen to their arguments and cry. That's when I started thinking something was wrong with me. I'd lose sight of myself I wouldn't know who I was. I'd act strange. I'd love the sight of myself bleeding. I feel different from my friends like they won't understand me. I hear them whisper my name in my head in the night. I get paranoid that someone is watching me and the voices don't help. I'm really scared of my mind and mood swings and so confused as to if and which mental disorder I have.
[Edited by @QuietMagic 11/20/21 to add TW]
I started suspecting something was wrong when I was 9. I was at summer camp and I was envious of this kid with no legs because people would carry him around. I remember trying to break my own legs just so someone would care about me.
It was probably in Grade 5 though, I was 11 and the teacher sent me to the office after reading my writing saying it was disturbing. It was about a girl who wanted to be a boy so she created a new identity or something. But I was so shocked when the principal said that's not what other 11 year olds are thinking about.
That's a tough question... I think I realized something was wrong with me when, at age 7, I would scream and cry about how ugly I am and how much I hated myself. As I grew up I started writing stories about suicide and self-harm and now that I'm 17 I still haven't gotten help for any of these issues at all, and it's kind of destroying my personal relationships