You already know how to be fair to somebody in a bad patch. The words come easily for a friend: it was not all your fault, you are not unlovable, this will not always feel like this. The same sentences turn awkward aimed at yourself, not because they are less true but because there is nobody in front of you to be kind to. The skill is there and the direction is the problem.

Remember what you actually said the last time you talked a friend through something. Write it down and change the name to yours. Say it out loud once, even if it feels theatrical.