try:

=IF(IF(Q191=4,"1",IF(Q191=3,"2",IF(Q191=2,"3",IF(Q191=1,"4",IF(Q191=5,P191)))))=FALSE,P2, IF(Q191=4,"1",IF(Q191=3,"2",IF(Q191=2,"3",IF(Q191=1,"4",IF(Q191=5,P191))))))