I took a job 3 months ago and it's already a disaster. This was a huge mistake but how long do I have to stick it out before I can look for a new job?

This can happen to any one of us, even if you feel like you did the best research. It's tough to know what it's like to work a job inside a company until you're entrenched. It's always a risk and we try our best to mitigate it, but with everyone on their best behavior in the interview process red flags can be elusive.