15 month sleeps like crap after 2 am?

Ever since she was about 7 months old my 15 month old barely sleeps after 2 am. Up every 30 mins to an hour till she’s fully awake at 530 in the morning. It’s killing me. I’m basically up from 2 am, work 8 hours and then medical school after she’s asleep. I’ve been running off of 3 hours or so of sleep for month and honest to god it truly feels like dieing. My weight loss has come to a full stop. I’ve never in my life drank energy drinks and now it’s all I drink. It doesn’t matter how many naps she gets, nothing has mattered. So many things have change since she was 7 months old and nothing has changed the way she sleeps. She has always been the worst sleeper. When the eff is it going to end?? Surely by 24 months of age she should be sleeping through the night. Im losing it.

Sleep environment: she has been sleeping in crib since 4 months old, noise machine, tower fan( does not blow on her). I had her fully sleep trained at 7 months old. Around 8 months old she was hospitalized for 8 days for a very serious viral infection that Caused a fist sized lump on the side of her neck. After that hospital stay she never slept the same again, it ruined all my effort into sleep training. She cries until vomits..every..single time. I can’t put her in the crib and leave the room. They had some pretty scary cage like cribs she had to sleep in, we were transferred 4 different hospitals. And I think it scarred her. When she wakes up I let her cry alittle or do her thing before I go in there just in case she falls back asleep but once she gets herself standing she will stand there and scream till she vomits. Happens every time.