How do you deal with pressure from your parents?

Ok so after may when I will finish my college,I have to go to ireland to live with my sister and her boyfriend for all summer...,but the problem is I smoke and my sister hates smoking and her boyfriend hates it too,if I want to smoke I cant do it...

outside,my sister wouldnt let me to go outside alone and she wouldnt come with me...She wants me to hide that I smoke from hers boyfriend but he knows anyway from last time when I visited them...if me and my sister,if we go on shopping,she feels ashamed and she wont let me smoke..So I want to quit smoking and I also want to loose some weight before I go,but I cant do it,because there some much pressure from my family to be smart and good...I only got one mounth ans some weeks to loose weight,quit smoking and finish college with good grades..I so need help,how can I do this things,if there isnt so much time left and all that pressure coming from everyone,especially when things arent so good at home..?

the studying part and good grades I shall not comment, because I am way behind in that so I cant really give advice there, just dont stay studying for to long, literally, you could get sick, and that would affect everything else your trying to update!
in the losing weight part, if you wake up early, maybe walk for a mile, or 2, or go to a gym, if you dont really have time for the gym, try to find moments where you can walk for at least half an hour, change your diet, and drink lots of water.
and the quit smoking part... use a patch maybe, or those flavour gums to help you quit, and buy a lot for when you go to your sisters.

oh and for the main question, I think you are a good and smart girl, because your asking for help, and thats smart, and you want to change, and for the better, and thats good plus plus smart, your parents should be proud of the changes your trying to make in your life.
thats all I'll say becuase I dont really know your family situation.

I really do hope some of this helps you
GOOD LUCK!!! and hope you have
a safe flight!^^

worry about the weight thing not so much while you're trying to quit smoking bc it will just make things worse and you not to quit smoking even more...
just cut down, like if you smoke a pack a day for a week go with only 3 or 4 packs that week. and just keep cutting down.

You're going to hate my answer but I just quit when I was too poor to buy any more. No choice really. It sucked like hel but DO NOT START A LIGHT.

Dont know much about weight loss.
Dont know much about study either sorry.