Confidence sounds like a feeling and behaves more like evidence.
The reliable kind is not a mood you summon. It is a list you can check.
You have been through something before this. There was a period you were certain would flatten you, and there is a scar somewhere to prove it happened, and here you are years later reading things on a screen.
The list is not inspirational. It is a record. Difficulties have been left behind before, by you, using roughly the equipment you have on you now.