Okay so ive actually done this so not guessing. You get nausea (bear in mind I didn't take a tonne load), I vomited for about 24 hours until I hot taken to ed (it wasn't a suicide method but woulda been happy to die). I ddnt have much pain, in fact even the nausea wasn't as sickening as many nausea bouts I've randomly had, but I did basically vomit everything I tried to drink.
In hosp my hr went down low but when I woke up they said I could be discharged if I could get it to 60. I stood for the first time to go to the bathroom (was on a heart portabble monitor thing) and literally drs came running because my heart went into a non beating rhythm (idk the technical term), i was then sent to coronary care, wasnt allowedd to stand, and it took 5 days for my heart to get a more normal ecg. I was still not well after that.
This was a small amount (like a few flowers, maybe a leaf or two & a stem. I can't speak for how bad a heap would be but I hope to use this method soon