Thinking to leave them ?
If you are in that stage of thinking — It's the right time to quit !
Once you have answered to all of these and many more thoughts that will cross your mind during this process , schedule for an open conversation with your manager or HR partner ( or anybody who is a superior and you can open up to). If you are still convinced that you did your best and the company failed to provide an environment for you to learn and grow and is unable to fix it for you, communicate the same and plan to move . Leave on a good note.
Remember to be honest while assessing yourself , otherwise you will fall into the same trap in another company and waste hours cribbing about the leadership , management , team , etc.