I don't go out at night because I'm a loser
That can't be true. Why do you think you're a loser just because you don't go out at night?
I'm a loser because I stay in home
You shouldn't call yourself a loser just because you want to stay at home. Not everyone goes out at night. There are people who have fun inside their house.
I cannot meet people outside. There is no point in going out when your friends are all on Instagram, Snapchat, etc..
Well, it's perfectly fine for you to stay at home as there can be a lot of activities you can do like watching movies or playing video games, or even invite your friends over. I do hope you do change your mindset that your lifestyle is for losers as it is simply not true.