Ginny would probably start with simple but heartfelt words like 'Shh, Harry. It's okay to cry.' Then she might continue with 'You've carried so much on your shoulders for so long. Let me help you carry some of the weight now. You're not alone, not ever. I love you and that means I'm here for the good and the bad times.'
Ginny might say things like 'Harry, you are the bravest person I know. You've been through so much and you've always come out on top. This is just another bump in the road, and we'll get through it together.'