Austerity means- when we are putting our own feelings and thoughts in a place where it doesn't interfere with our service to please Krishna. If we don't feel enthusiasm then we should act enthusiastic with eagerness. If guru wants to be eager to do deity worship or distribute book or preach to others or serve to Vaishnavas or whatever we're doing that eagerness to please Krishna wheather we feel eager or not is a detail. We're eager for Krishna's pleasure not for our pleasure, that's mood of a servant to be eager to serve.
It's from jagannath Puri yatra 2023 lecture You can watch the whole series of lectures from the playlist - ru-vid.com/group/PLpiMDolWM-hMVtcxmwYvH0KVIsx2k4--8&feature=shared
