First of all, if your family has bought you a house in Beijing, your life may be a little easier, because you don't have to pay the mortgage or rent. If the living conditions in Beijing are a little better, the monthly rent should not be less than 2000 yuan, and the rest 1000 yuan is for your own living.
Having said that, in addition to the rent, there are incidental expenses and 300 yuan per month, and then it is almost unrealistic to leave a month's food expenses below 20 yuan. It would be better to do it yourself, but it costs 600 yuan a month, so there is almost more than 100 yuan left, that is, 100 yuan or more, plus occasional bonus or overtime pay, to buy a dress.
Although it is not that you can't live with such a high monthly income, how much money will most people have left after meeting their basic needs with such income? Do you have enough money to live on? Do you have enough money to meet your girlfriend's needs? Although it is realistic, it is a fact! Instead of thinking about how to live happily with such a small amount of money, think about how to get a promotion and a raise!
But in any case, if you want to have a happy life, then satisfy the status quo, be frugal and cherish the happiness now!