Is there a way to quit graciously with short notice?

I just accepted this job 5 months ago and feel like it was a mistake. The workload is too much for me, and the work environment is too toxic and exhausting to deal with on a regular basis. I’ve been seriously considering becoming a tour guide for a company that organizes events like a Ukraine ski trip and city tours. The benefits are great, the salary is more than enough, and I think a fresh change in environment is exactly what I need. Is there a way to quit gracefully with short notice? Do I have to state a reason why I’m quitting? Is it better to send a formal email or express my resignation verbally? I need some advice!