Hello Hua Li,
I am very glad to hear from you,and I read your message about your problem.I am going to give you some advice,I hope that could be helpful for you.
Firstly,you do not need to think too much about how people thinking,for instance,they should not laugh at your figure,it is their fault.
Secondly,even they did in a wrong way to you,I recommend you to treat them friendly,do not argue with them,in addition,you may have some nice communications with them.
Thirdly,I strongly recommend you to do excise everyday to lose your weight,and keep your fit,this is good for you health.