I’ve given up hope on her sleep

My baby is 6 and a half months and her sleep is just terrible, and I’ve tried everything, sleep training did nothing for us, feeding her when she wakes up doesn’t help because she just continues crying after she’s done, I put her down at 8 and she wakes up at 9, 10, 11, 12, and then 2:30 and she’s up until I feed her at five, and I HAVE to wait until five to feed her because only then will she actually fall asleep by me feeding her, if I feed her any early, there’s no hope in her sleeping for a few more hours, maybe another hour, and no it’s not her teething or a sleep regression because apparently she’s been teething and having a sleeping regression for 3 months nonstop, her first 3 months she slept beautifully, I put her to sleep at night and she slept until 7 am, I’m the first month she did wake up every few hours to feed and went back to sleep with no fuss, but now it’s 😫 I tried putting her to sleep earlier and later, tried keeping her up longer before bedtime, followed a strict schedule, let her nap whenever she wanted and however long she wanted, none of that helps, my grandma gave me a tea that she used to give her kids and my whole family would give their babies to help them sleep when they were for sure teething and they would sleep so well at night, but my baby? Nope, it actually made her sleep worse, I have tried every trick in the book, I only get 2 maybe 3 hours of sleep if it’s a good night, every single night for 3 months now, not to mention she only sleeps in my arms, and it’s not that I taught her to do that, nope, as soon as she started sleeping bad at night, her naps went to crap too, if she wasn’t in my arms, she’d wake up in 5 minutes, and I just don’t know what to do, the house is a complete mess because if she’s awake she screams bloody murder if I walk away and obviously she naps in the arms now, and of course I try to clean when I put her to sleep for bedtime but it’s like she doesn’t want to sleep at all when I’m cleaning, there’s a noise machine and everything and she’ll still wake up every 5 minutes on the nights I have some energy to clean.... I just don’t know what to do anymore, I have given up all hope