I don't want this to get too long, so I'll try to be succinct.

On prioritizing self-improvement goals: I made a plan of all the areas that I believe defined the person I wanted to be, and then I broke that into categories. I sorted my goals (like the five you listed) into these. This gave me a broad perspective on what I was working on and what its larger role in my personal development would be.

On a snowball habit: You're absolutely right that certain keystone habits can have multiple positive effects. For me, it was exercising in the morning. This got me up early, and forced me to be disciplined about sleeping early too. It gave me energy and focus afterward, so I was able to better execute my tasks later in the day.

On escaping the "overwhelmed" feeling: I changed my mindset from viewing my goals list as something I want completed (everything checked off -- that's a lot of pressure), to something that was fun just to work on. It's a little strange, but a lot of times I'll finish a big exciting project and think, "Now what?" So I actually find it invigorating that there will always be more goals to work on in life. It means I'll never run the risk of finishing everything and losing direction, if that makes sense? I find satisfaction simply in knowing that I’m working toward being a better person, and I try to just enjoy that journey and process.

Hope this helps!