It might seem easier just to let things work themselves out and put off having a difficult conversation. However, avoiding a tough topic just makes things worse.  Instead, ask her to set aside time to talk about an issue. Say, “Hey, I know you’re upset about what I did the other day. I’d really appreciate it if we could take some time to talk about it.” Keep in mind that putting off these difficult issues will only make matters worse over time and end up slowly poisoning the relationship. Tell her, “I want to have a calm, open conversation about the issues we’ve been having,” or “There’s something I need to talk to you about, and I hope you’ll keep an open mind.” Try to recognize when you stonewall, or when you resist opening up to your girlfriend. Try to think about your reasons, and explain them to her. Tell her, “I know I’ve been closing myself off to you. I’ve been reflecting on why, and I think it’s a defense mechanism. I’ve always been the type to put up walls and I hope you can be patient with me as I work through this.” If she’s not opening up to you, try not to take it personally. Be empathetic instead of giving up or putting her on the spot. Be detached and understanding if she’s closed herself off to you. Say, “I don’t want to force you to talk about your feelings or put too much pressure on you. But I hope we can get to a point that you trust me with your emotions. I promise we can talk openly and calmly with each other about anything.” When you start a difficult conversation, try not to shy around the topic. Whether you want to talk about becoming more intimate or have to work through a problem, share your intentions clearly and confidently from the start.  For example, say, “I’d like to talk about taking our relationship to the next step. How do you feel about intimacy and being physical with each other? Do you have any expectations about timing?” Ask her, “Can we talk about when we hung out with your friends last night? I felt really left out. I don’t want to keep you from socializing, but...

How would you rephrase that briefly using Vietnamese?
Tránh trì hoãn những đề tài khó nói. Dành thời gian chia sẻ cảm xúc của bạn một cách thẳng thắng. Tránh tạo áp lực khi nàng chưa muốn chia sẻ cảm xúc với bạn. Chia sẻ ý định của bạn một cách rõ ràng và chân thành.