My girlfriend always says she doesn't like me. She is always angry about trifles. I really don't know why.

You must be submissive. You already think you love her. As a man, in order to please girls, don't be limited to giving or giving, but stick to your own opinions. If two people really love each other, you can say what you think, regardless of whether she will be angry or not. Men can't be too self-righteous, or they can be said to be timid. If you are angry, see what she will do. If she really loves you, she will reflect on herself and apologize to you. If she loves you not for money and vanity, on the contrary, do it.