The easiest way to commit yourself to leaving a job and to navigate explaining yourself to the company happens to also be the way you should always be leaving jobs: by quietly interviewing for other jobs.

Find a new role somewhere else that you like and accept it. Go back to your current team and inform them that you've enjoyed your time working with them, but you can't pass up the new opportunity.

The only problem I think you have here is that you haven't started interviewing yet. So, of course you feel aimless and uncertain about your next step.