Welcome to the real world.
But seriously, chin up, first and foremost, what's stopping you from moving out and looking for a room for yourself? When your parents could afford you send you over to the UK, I'm sure they can afford a couple of months rent for a single room? (averaging at about 250 a month depending on where you live).
You've been in the UK for 5 months no one strikes gold in a few months time it takes time, energy and effort to make something of yourself, there's no point in living with your brother if you two don't get along and need your space. Before all else your first priority should be getting your own room (one step at a time my friend) keep doing whatever job you're doing to have some sort of an income coming in, focus on your education because I presume that's how you came here, with a student visa, hence you're here to study and work should NOT be MAIN priority at this point, something your parents and you should have been clear about before you left Pakistan, and while doing so keep applying for AS MANY jobs as is humanly possible (been there and done that), no body is going to take pity on your for walking on a high street at below 0 temperatures, you are doing this for YOURSELF and maybe your parents, patience is key, it takes time you don't just jump on a ladder you climb one step at a time, and maybe 2 once you're slightly higher :D, but it's the first one that's the hardest.
Honestly, your thread made me laugh OP, what have you got to worry about? Think of all the people that would like to be in your position! You're living in a first world country with law and order, mostly educated folk from different parts of the world, you don't get that in Pakistan, what were you hoping to take back a case full of money once you went back less than a year down the line?
That being said, what are your qualifications? How good is your English fluency, written and oral? Please don't be like most of the folk that go to the UK, mess up their education and the lives by working for 5.50 an hour, don't run after money, make that b!tch chase you :).