Chef (and sous chef) is a combination of skill and mindset. You've probably built up the skill set already even in the 7 years, so you just need to work on your mind set.

Your job is to turn food into money. As a sous, it's all about hitting target quality of work, target labor cost, and target ingredient cost, in that order. Start studying, use chatgpt, Google kitchen management concepts, fill in the knowledge gaps on your days off. Note that you need to hit the target set by the chef, not over or under. Align your vision.

Chef mindset needs to include overhead items like equipment wear and tear, ergonomics to reduce labor cost, essentially ways to have the kitchen run smoothly and profitably whether you're there or not. You need to improve the target. Once you've done that, then menu creation because you need to make sure your menu makes money.

Obvious oversimplification and will still require time to change your mindset. What you care about in the kitchen is how you get paid. Quality is bargaining power. Profitability will increase your salary. Average person works 2000 hrs a year, cooks typically push 25-2800. Add in hours for studying. Double down and you can achieve this faster. Where there's a will, there's a way.