Ask HN: How do you manage large projects?

I quit my job a while back because I wanted to work on a problem full time. It's been over a month, now and it feels like I can't make much headway.

It's not a complex technical task. I set goals for the week when I start and work towards them but it seems like the week concludes and I don't have much progress.

I write things down. I use Todoist/GH issues to keep track of tasks. I try to formulate what I want to do for the next week. These little tools are useful but I suspect they aren't my real problem.

I can code just fine. I love programming! But I need guidance.

Where did you learn to manage large projects? Who taught you? How do you manage large, new projects?