sorry to hear things arnt too good for you at the moment. i dont think there is anything wrong with you, your just going through a rough patch in life, you might not know it but you could be doing something without realising your doing it. i never realised it when i did it but after getting told by some stranger that i looked like a miserable pr**k i asked my mum and sister and they said i do it aswell, but i never really notice i do it.
as for family acting mean towards you it might be you just need a break from each other, it used to be like that for me at home but i moved out for awhile and when i came back everything was alot nicer, sometimes ever a shortbreak like a weekend away can help (if you can afford it, send your mum and sister to a spa or something for the weekend, they will be gratefull, happy and relaxed when they get back)
you will meet bullies where ever you go, i got bullied at school and even when i finished school, its the way the world works im afraid, theres always going to be people that act like that, dont be afraid or hate them, have pity on them.
if your friends act like that towards you then they are clearly not real friends, i cant really talk much on this subject as i have had bad dealing with friends to the point i have next to none but thats my fault i prefer to be alone.
a real friend for me is someone that care's about you and helps you when they can no matter how bad things get for you in life, when your sad they make you smile, when you lonely they comfort you and make sure your not alone, they like you for who you are and dont tell you to change, there honest but not cruel, trusting, stick up for you when someone is being mean or bullying you.
true friends are hard to come by but when they do that person is a 1000 times better then any person who wants you to change because they dont like something about you.
ive been through most of what you've gone through and still have some problems like lack of friends but as my dad always told me
"life isnt a straight line, its a curvy road with its ups and downs, when your at the bottom you will feel like giving up but just remember if your at the bottom you can only rise, but dont get too comfortable when your at the top as you could fall back down at any time"
it may sound kinda cliche but i believe in his way of thinking, sure my life sucks but i know im not at the bottom anymore, im rising back up, even if its at a slow pace.
best thing you can do is try to keep a positive mind and keep smiling, no matter how horrible things get, but if your ever feeling down just come find me and il be there to talk, listen, be screamed and shouted at, no matter the problem il be there to help in what way i can.