when dear son was around your baby's age, he nap longer, around 1-2 hours each time. about 3-4 mths onward then he started to nap 30min for each nap but he napped for 4-5x each day. and currently, he nap 3x per day. usually btwn 3omin-1.5hrs. add up will hav around 2hrs-2.5hrs.
honestly speaking, you can consider pacifier, cos pacifier can gives babies a sense of security. =)