You can be scared of heights and still ride the coaster for your little brother. Love borrows courage.

Love does not cancel the fear, it just stops the fear from being the deciding factor. That is how most courage actually operates, and it is why people manage things for somebody else that they would never do on their own account. The borrowing is real, and it leaves you with something you can use later: you have already done a frightening thing while frightened.

The next time your own fear has you stuck, ask what you would do if a younger kid were counting on it. Then do that version, and remember you have done it before.