1. Never let your girlfriend go to sleep upset. Never. It gives off the impression that you don’t care when she needs you most. Persistence is key. She has a soft spot for you (after all, you are her boyfriend) and eventually you’ll get through to her. If you know your girlfriend is the stubborn type - Try, try again.
2. Do not reply to her feelings with “lol’s” or “hahah’s”. Nor do you tell her to chill. OR that she’s whiling out. What is that really supposed to accomplish? To be honest, it pushes all the wrong buttons, adds fuel to the flame, etc. Would you rather her go to some other guy to talk about her feelings? Cause I’m sure she has plenty. She goes to you for a reason, so take time to try and understand her. Not shut her down.
3. Solve things as they come, and not a day or two after. Things don’t calm down over time as you probably think they would. It gets worse now that she’s had all this time to think. Don’t assume things have magically fixed itself - Take the initiative upon yourself to make things right.