that's a horrible thing for someone to say
am sure it's not true either, heck I know people on here would notice! (even if they don't always say, am sure people notice when people don't post in here for a while without saying why!)
is it possible your friend has just been busy with things after her exams? maybe try and call her at some point and chat? hopefully it's not a case of her actively ignoring you or anything!
you aren't worthless at all
and you don't alienate anyone here for a start im sure!
that's okay, we all have times where we don't feel up to posting and stuff, hopefully you feel that when you are able to you can and will get support here
isolation is so easy when you feel down I know, sometimes it can be good just to get out though if you can, even just to the shops for food or something, a bit of daylight can sometimes be just what you need to feel a little better that day (I find this sometimes anyway, but don't tell my mum this or she would send me out there all the time which would scare me
)
your personality is still there im sure, it can be easy when you get really down to lose your sense of self though so that's understandable, just try and remember the things that you enjoy or even just make things a bit more bearable right now, that's a good place to start