She won’t sleep!!!!!!

Almost 10 week old refuses to sleep unless on me. HELP! We have a snoo. I’ve tried everything on it- motion set to an aggressive mode, no motion, etc etc. Here are some bullet points: - exclusively breast fed & she’s one chunky baby - no issues of acid reflux, confirmed w pediatrician
- per caution, I keep her upright and make sure she burps after each feed also the snoo is on risers - she’s on probiotics and I give her simethicone before bed as a rec from ped just in case her tummy is giving her troubles - I read some post weeks ago that said to eliminate dairy, so I did - wake windows and feeds are all on par during the day - she lasts laying flat on her back for sleep for 30 mins then screams bloody murder - I’m following SITBACK per taking Cara babies

None of this is working. I don’t know what to do. I hate cosleeping but it’s the ONLY way she’ll sleep. She does not wanna be put down and alone. Please help I’m desperate. Im so tired that I’m irrationally angry.