As valuable as a routine can be, IMHO you're putting the cart before the horse. The root of your question is "What should I be doing?". That can't be answered

As valuable as a routine can be, IMHO you're putting the cart before the horse. The root of your question is "What should I be doing?". That can't be answered by adopting a routine. Better to start with your goals (not too many of them) and then work out what you think is the best course of action to achieve them, then create a routine around that plan. Even once you have goals, there's a big question of how rigid a routine is optimal, which is a highly personal question. I've found that process and routines should be minimal to allow for greater focus on actual work with more space for first-principles thinking, but that's just me. Find what works for you.