Insane regression

[Izbomb]

At 3 months she was doing a 5 hour stretch, feeding and a few shorter stretches after that. She'd nap for 30/45 mins at a time in her cot.
Hit 4 month regression, teething and was ill all at once. Now nearly 6 months and will only fall asleep feeding or being rocked. Wakes up screaming every hour. Takes multiple times to go back down. Will nap max 30 mins in her cot during the day, but that's a good day.
Never used to wake up crying, was always happy and easy to settle.
I think we will start sleep training to get her falling asleep independently, but any advise as to why she's so upset would be great. Tips welcome too! (Still exclusively breastfed, starting solids in the next week)

Literally could have written this myself. Exactly same as you. Lack of sleep is destroying me

No advice but at least we're not alone.

What I've been doing:

Last night and tonight I'm trying a method where I feed her, then put her down drowsy to try to get her to sleep. Of course she then screams so pick up, calm down and try again. Rinse and repeat. Took just over an hour to get her to sleep tonight.
Last night it was quicker but then I was woken up every 90 mins, I just fed her, held her for 15 mins sleeping then transfered her.

Naps in the day, no idea what to do, mainly contact napping as can get a longer nap in which she desperately needs but that's hard on the 4 days I've also got a 3 year old wanting attention or wanting to play with baby

Let me know if you find anything that works!

So glad it's not just me!
If it's any consolation, she seems to have naturally been a bit better over the last 3 nights and has done some longer stretches. So hopefully this happens for you too.
Naps wise, I can get 45 mins in her cot so she does that in the morning and then a bigger contact nap in the afternoon. But I just have her so can manage that.
Hope things improve for you soon!