self esteem

Hi, I have almost no self-esteem. Before marriage my family never allowed us to go out . I have very bad eyesight b/c i started studying too much to get rid of other problems. my sister always fought me before marriage. when ever someone treated me well, she started being jelous of me and ended up in fighting which i hate. Unfortunately she encouraged me to get married with her husband's younger brother, i did that b/c i was angry to my mom's behaviour. B/c she did not inquire about my husband at all and she made me get married even though she knew about my sister nature and jelousy about me. Now i m very depresed b/c it has been almost 5 years of my marriage and my sister has same nature of making me feel bad. my husband is also clever and her husband is also a trouble. her's is very lazy and did not even buy his own home. her kids make my home like a hell. they bother me all the time and i can not say anything b/c my husband love them. My family lives in other country, i have met them only 2 weeks after marriage. since then i have not been there.
i have lost my self-esteem b/c of all theses people. if i try to make friends my isiter start behaving very bad with me and i can not tell anyone and just leave making friends. people, like husbands friends's wives and famies are very jelous and bad women.
please tell me what to do, i m complete lonely. i want study in university but i have so many problems such as money, eyesight etc.