1 week after Rhinoplasty, have woken in middle night with severe bleeding, including passing clots in my mouth.Is this serious?

This is something you need to seek immediate and urgent attention for from your rhinoplasty surgeonIf you cannot get hold of them then have a family member take you to a local hospital emergency department for assessment - severe bleeding 1 week after a rhinoplasty can be significant and dangerous and if not stopping may require a return to surgery for packing to top the bleeding

Thank you very much for enquire.

It's too early to make value judgments with only 1 week after a rhinoplasty.
Swelling after a rhinoplasty depends of the surgery complexity.
In this regard, the nasal swelling Post-op It can last from two weeks to two months.
To reduce this swelling, I recommend you perform delicates daily lymphatic drainage massage therapy over the face (around the nose) avoid sun exposure, and take pain/inflamation pills, as your surgeron precribe you.
Kind regards, 
Dr. Emmanuel Mallol Cotes.-  

having clots in the back of your throat 1 week after surgery with "severe" bleeding is certainly outside of what is expected.  I suggest you contact your operating surgeon immediately and seek an evaluation as soon as you can.