You already did change of status from TPS to F1. You gotta withdraw and re submit . Grounds of denial by immigration people. Now you want go back TPS, ok on what grounds? Are they extending TPS for Nepal? Or You think they might extend TPS for Nepal cuz of Corona. TPS- find job, sponsor thru family, marriage to citizens, Assylum, H1b , F2, J2. F1 is not a bad non immigrant visa- apply economy hardship, with STEM degree u can work for more than 3 years. When recessions and health crisis hitting them hard, always remember their first priority be their citizen and LPR. See what the Australian PM said other day.