This came together really nicely. Something I'd add to #4 is that "venting" when you feel bad is only occasionally useful, and pretty reliably keeps whatever you're venting about at the front of your consciousness.

A friend pointed out to me that when one feels depressed, one acquires blinders about the past and the future. After he suggested this I started noticing it--on a really bad day, it felt like all days were really bad. If I couldn't get ahold of someone for some company, no one ever wanted to see me. Noticing this consciously was incredibly valuable, because it led me to second-guess those judgments when I was making them. It became a meta-signal that I was in a funk and needed to get out, like a lucid dreamer taking control: "I haven't seen anyone in weeks. Wait--that's not literally true. I was out yesterday. I must be in the mindset where it seems like things have been horrible forever. Okay, time to reach out for what I need to get out of it." Then I check for hunger or tiredness, fix those if needed, find an activity to distract me, and let someone who cares about me know I'm feeling down so I can get some support. This system isn't perfect, but it's a hell of lot better than getting dragged across the floor by a foul mood.

A couple notes of housekeeping: I would suggest adding a summary break, and also putting title caps in your title.