What would you do if your cousins were teaming up against you?

My two cousins and my aunt are teaming up against me ..they would do anything to make me a upset. I have stopped talking to one of my cousins for a few years now due to her extreme jealousy, and some family problems between my mom and her dad. She is extremely jealous!!!! When I got accepted to University and moved out of my town to start school in Toronto she was not even at school because she was kicked out...When I got accepted to University ..she kept telling me how jealous she was that I got the opportunity to move on with my life, and she was stuck in that little city ...She started taking night school cles, and eventually got accepted to one of the universities in Toronto after a year...I have already graduated and I am in second year of my masters, and from what I have heard she is struggling with school . I do not like her because she sleeps around with boys, and can't keep a relationship for longer than a few months....plus for her it's ok to date other people's boyfriends. I have always been a very good cousin to both of them. When her ex bf asked me out I told him that I could not go out with him since he had dated my cousin, and since he had broken her heart I would take a revenge by saying no to him. My other cousin who has not moved to Toronto has always been like a sister to me, and she also did not like the other cousin...she always told me that she can get along with me because I am down to earth like her,,, and it's hard to get along with the other cousin since she has changed alot , and the group of people that she hangs out with are girls who only care about clothes, make up , and latest fashion..I love fashion too, and spend tons of money on shopping, but since I have started my masters I have put on some weight...all three of us used to be skinny, but now they are skinny, and i am the fat one...well I weigh around 150 pounds..and I used to be 120lbs before....my good cousin got married a month ago ,, and since then the bad cousin has been trying to get so close to her to piss me off...at her wedding we were all her bridemade ..but she kept calling herself the maid of honour even though the bride wanted me to be the maid of honour,, I was the one who she chose to give a speech,,,and my cousin (bad one) was extremely jealous...anyway ..before the wedding she gave the bride a necklace,,and I didn't give her anything since our family had already bought some expensive stuff for her...plus I didnt have the money...during the wedding she kept holding up my cousin's dress everytime she needed to get up ..and she wanted to do her first dance..she wanted all of us to go with her to hold her dress up ..but my bad cousin said that we should not all go,, and only her would be enough..to which the bride surprisingly agreed....everytime I wanted to dance with my cousin she would come and dance with her so I would have to leave...she just does not want me to exist ..after the wedding things have changed alot....the two cousins are sooooo close to each other ..they would do anything in their power to piss me off....I confronted my cousin a few times,,and asked her why she has changed to which she said she has not ..My aunt has also joined their team as well as my uncle.......Last week I posted a video of myself teaching my anatomy cl which one of my students had recorded on facebook....I never got any comments on that from my aunt or uncle...but I got nice comments from everybody else...but as soon my cousins post a pic..my aunt and uncle are quick to comment on theri pics and tell them how beautiful they are...the same aunt and uncle that used to think I am beautiful, and smart...I have both the looks and the brians....My cousin( good) keeps coming to toronto to visit this other cousin, and they keep going out..and posting pics on facebook....I have been under alot of stress lately to a point where I have got severe bronchitis..because my immune system has been weakened....I really donno what to do ..I needed to get this out...and found no better place....