Joe (he/him) presents with a sudden onset of vertigo & nause…

Joe (he/him) presents with a sudden onset of vertigo & nausea yesterday when he got out of bed. The results of your positional testing are as follows: Roll Test (-) bilateral, R Dix-Hallpike no nystagmus but a few seconds of mild dizziness, L Dix-Hallpike showed robust L torsional upbeating nystagmus with a latency of 13 seconds & duration of 48 seconds, with Joe becoming very vertiginous & nauseous. What is your diagnosis?