Can I use my own link?

No. A referral has to be somebody else. Buying through your own link, signed in or not, is not credited.

What pauses a link

One card behind several referred accounts, or a referred account paying with the same card as the ambassador, pauses the link while a person looks. Pending commissions are held, nothing already earned is lost, and you get an email you can reply to.

What is fine

Referring family, a partner, a roommate, a classmate: anyone who is genuinely a different person with their own account and their own card.