You could argue that the famous story of the theft of Mjolnir by Thrym is a fear-related story. Thor is forced to don a humiliating role and wear a wedding dress to disguise himself. He has to relinquish his usual power and might to stoop down to Loki’s trickery in order for them to retrieve the hammer. Thor is more or less afraid of his loss of dignity in society and must give up his imposing status to gain back the one thing that can protect the gods from the forces of chaos. In this sense, it may be more of a sacrifice for the greater good of the Aesir.
Odin’s sacrifices to gain knowledge could be fear related, but they’re really exchanges to obtain a selfish goal. Although, some of them can be stretched to fit your construct.
Loki’s fear of the gods’ threats (mainly Thor’s), in many occasions, cause him to rectify the mischief he has caused. Two examples are the story of Idunn and her apples and of the creation of Thor’s hammer among other powerful items.
The gods’ fear of Loki’s children led to a series of misfortunes, and probably doesn’t aid to your question. On the bright side, they got a ruler of the underworld out of it. Yeah, never mind, that doesn’t work...
A very symbolic overcoming of fear occurs when Sigurd rides through the ring of flames to wake Brunhild. Really, this was Gunnar’s fear of riding through the flames and Gunnar’s love for Brunhild, but Sigurd is the one to triumph and achieve Brunhild’s undying love. Although, it all ends rather badly for the trio.
I hope at least some of that answered your question. Have a nice day.