It took me a long time to learn that it can be very valuable to stay in the loop with PMs and planners. Once, I was tearing my hair out over a huge task, and literally on the verge of quitting in shame, having realized it was beyond my ability to even move the needle on that mess. Fortunately I happened to vent about it to a PM, and she just says, "Oh don't stress out about that. That's getting cancelled." I don't know who was going to tell me or when. But as a mechanically-thinking engineer, my only solution to this was to figure out how to move the moon with a lever. Their solution was one line in an email that said, "Cut it."