It would be great to see the X-ray, but considering there was two opinions and they both said it wasn't broken that could be a good sign.
Blood in the joint, or haemarthrosis could be due to multiple reasons. You're knee is definitely very swollen. Due to not being able to weight bear on the knee, it would be ideal to order a CT scan to check for any minor fractures that didn't show up on X-ray. How long are you in Vietnam for? Other reasons for haemarthrosis could be ligament tears like an ACL.
My advise would be to stay off the leg as much as possible and keep using the crutch - even find two so you could go totally non-weight bearing.
If you need an online consult, I am happy to see you via video consult, I've attached the link for your information:
Hope that helps!
bit.ly/2v6qaHo