You have a ton of good material in there. My first suggestion would be to change your intro a bit and get to the meat of your argument sooner. You start out with an explanation of why a daily gratitude journal is good but the premise of your article is that you struggle to maintian that long term. You need to address that point sooner.

One easy fix would be to take the final two paragraphs of your intro section (the ones just before the three dots) and lead with that. Your structure would then be, 1. daily gratitude is hard when life is crappy, 2. here's why daily gratitude is good and I started doing it in the first place, 3. here's how I fixed it when it got hard.

Tightening it up a little bit would probably help too but you have some truly excellent content in there.

Publishing it in a publication probably would have made a difference as well.

All in all, it's a great piece. I don't think you were preachy or dismissive at all. I agree that simple cheery self help seems to do better here than the more introspective realistic stuff but I for one appreciate your realism and I'm sure I'm not completely alone.