She just won’t sleep 😢

My little girl will be 5 months next week and she is awful at sleeping, especially during the day. She used to do a good 4-5 hour stretch at night but now we’re lucky if she makes 2 hours before waking..she only manages 20-30 minutes during the day for naps as well and just does this all day. I have tried to get her into a routine so she knows what’s coming and nothing is a surprise as read that is meant to help and also tried controlled crying with her where I go in at timed intervals but this doesn’t seem to help. I’ve done white noise too. I feel exhausted as I also have a toddler to look after and a husband who leaves the house at 7am and is gone for a 12 hour day. Any advice others can give to try to get her to sleep for longer would be so much appreciated xx