I have had mixed results with lists. When there’s an obvious priority for each task, i.e. I can just complete the tasks in order, I am a machine. When I need to prioritize and order the tasks, I end up paralyzed and crash hard.
Prioritization will depend on your goals, so it is hard to give specific advice. But I will say that defining your goals is the first step. Once you have those, you can figure out which tasks take you towards those goals most effectively, which tasks are blocking others, and prioritize accordingly.
FWIW, I split my tasks into three lists - Personal Tasks, Home/Property Maintenance (I live on a 40 acre hobby farm, so this adds up), and Work Tasks. Personal Tasks are driven by my goals to stay healthy and create artwork. Home/Property tasks are driven by my goals to increase food production at my home and improve our self-sustainability, and Work tasks follow my employer's goals.
Your goals likely won't match mine, but a similar breakdown might help.
Prioritization is the hardest thing for me. If you follow GTD, working on Horizons 2-5, especially 4&5, make a big difference by recognizing what your purpose and visions are for your life.
With that, prioritization has become much less challenging for me.
I deal with this same problem every day. But I reach out to different business people and construct a priority for my team. I would say your manager should be setting priorities for you.
Do you have any advice in this regard?