4 month sleep regression ?

My daughter is a little over 4 months (18.5 weeks) and for a month now, she has not slept well at night. She used to sleep through the night at least once a week, and would typically only wake once or twice. Then just out of nowhere, her sleep has gone to absolute shit. She’s waking up at MINIMUM once every hour. Sometimes multiple times an hour. Most of the time it takes 30-45 minutes to get her back to sleep. She has random stretches where she wont sleep for 3-4 hours in the middle of the night. The longest stretch she’s slept in the last month is 1.5 hours. I know theres a developmental leap / sleep regression for this age, her doctor’s only advice was to reduce her naps during the day, but shes never been a good daytime napper. She has maybe four 30-minute naps a day and thats the most i can get, she wont nap more than that. When i’ve tried cutting back, shes just extra unhappy and doesn’t sleep any better at night. But I’m losing my mind. I’m so miserable and angry and tired all the time. I have zero patience anymore. My husband helps, but hes away for a week and we’re only on night three and i feel crazy. There has to be something we can do. I’m breaking down sobbing every night because i desperately need sleep and i cant get any. He keeps telling me this cant last much longer but it hasnt stopped and it doesnt feel like its going to.