I'm gonna be giving a bit of contrarian advise here: don't force yourself. No-one asked you to do this all, so take it easy and one bit at a time. If you are a volunteer, just have some fun with it. When you don't feel like continuing anymore, don't.
Another piece of advice: "if you want to go fast, go alone; if you want to go far, go together". (But the latter is more work). If you live in a medium-sized (or bigger) city, maybe there are a few people interested in joining? Post to the local facebook group and do a small gathering with a cup of tea and map together.
You forgot https://mapcomplete.org in your list!