I-94 should be issued to anyone who enter USA legally. There is no away u can enter USA from POE without I-94 issuance for u. There should be stamp in yr passport for the duration u r given to stay in US. If u leave USA within the valid period, no more problem for u when u r coming again next time. BUT when u are going back to Nepal pls be in airport before time caz they may ask u I-94's details. U can shoe the VISA stamping so that they will be convinced and ease happens. POE will issue u new I-94 in yr next visit. For yr convenience u can talk to USCIS that u loose yr I-94 before u go back.