So, a year ago when i was 19 i had the biggest fight with my mum sent me into a massive identity spiral and at the time wasn't getting my period (wasn't eating enough to maintain my physical activity) Did my own research online on "How to get period back" turns out i had to put on weight. Since 15 i've dealt with binge eating, i've always been a pretty athletic person and worked really hard to where my body was at. Sooo when i saw you "put on weight" i took it as a massive green light to do my biggest coping mechanism. The reason i wanted to get my period back was due after the fight i really resented my mum (who also deals with severe mental illness) and had those "i'll be a better mum then you moment" but lol how was i going to be a mum with no way of reproducing. So i put on weight and got it back, but the weight gain really messed with my head and the binge eating went to a whole new level. I use to be consistent with working out like 6 days a week but now i have lil to no motivation. After the fight with my mum that's when i can really pin point my bpd developed, everything i thought i was doing right was wrong and my self esteem was fucked up. Couldn't function at work, i isolated myself and every achievement meant nothing. It's rough when you've become so self aware and give yourself a hard time thinking "okay that happened a year ago time to get over it by now" never saying sorry to yourself and accepting what you've done.   
This is the first time i've typed any of this out, i'm very new to reddit and spent the last year on google and youtube learning about bpd and getting so consumed with information which can be super overwhelming. I'm just glad here's a place i find endless post's and people i can finally relate to and actually feel understood. Cheers Reddit :\~)