I thibk you should only do the things you enjoy. BJJ/understanding and knowledge of ground survival is important to be well rounded, the ground striking in the UFC is down by people using wrestling and BJJ principles to maintain top control and deliver strikes. But we aren't fighting in the cage or for our lives so do the enjoyable thing. I do bjj but not striking styles because I enjoy bjj. It took me a decade and an instructor with a dedicated beginners syllabus to understand the basics of survival in BJJ. Your coach is right, try to learn one thing a week and keep practicing that one thing all week. I would focus on a position, e.g. bottom mount, and ask your partners in all your rolling sessions if you can start from that position and keep trying to survive and safe yourself safe. Once you can survive, then focus on improving your position/escaping. This way you have goals each week.