I need help getting my 6 month old to sleep through the night. Letting him cry only makes him sick. HELP!?

My baby boy was on a routine by 2 months, sleeping through the night. He started teething around 4.5 months, and by the time he cut his bottom to 2 teeth his routine was shot to pieces. I believe I contributed to it by rushing to his side in the middle of the night because I felt to sorry for him. He was congested and miserable, he couldnt breathe and I could tell he was in pain. He has stopped teething now and is feeling fine, but can no longer go to sleep without being rocked and/or his bottle. He also refuses to self-soothe and must be put back to sleep when he wakes up in the middle of the night. I have cut out his nighttime feedings, but he still wakes up and just wants to play. He recently started crawling and pulling hismelf up, I feel like there is just too much that is distracting for him when he does wake up. My BIGGEST problem, however, is that I CANNOT ignore his cries because he causes himself to vomit because he gets so upset when he's left. So Im left with an awake baby who need a bath and needs his sheets and blankets changed. Someone PLEASE tell me how to get around this??? I feel like there is no answer because everywhere I look Im being told not to respond to his cries so he learns to put himself back to sleep on his own. All that accomplishes is lettng him roll around in his vomit. :( Some nights he'll sleep for 5 hours, most nights he wakes up every 2-3, and some nights its every hour. Ive tried shortening his naps so he is exhausted by bedtime, and that makes no difference. Ive tried music also. I need help before it drives me crazy.