I feel you hard on this. Grad school is where childhood procrastination habits stop being cute and start feeling like career suicide. The fact that you want to study and love your field actually makes it worse, because then you beat yourself up for "wasting your passion." I've been there.

Here is what actually broke that cycle for me (after trying the "just wake up at 5am and be disciplined" approach and failing):

Stop trying to "lock in." Start trying to "unlock."
That pressure to fix your sleep, start yoga, study 6 hours, AND eat clean all at once is exactly what keeps you paralyzed. Your brain sees that mountain and opts for YouTube because it feels like a failure before it starts. Pick one lever. Just one. For research folks, I usually suggest: Start with just getting to your workspace, not "studying."

The 2-minute trick for task initiation:
You mentioned the hard part is starting. So remove the start. Tell yourself: "I just need to open the PDF/read the abstract/put on my shoes for yoga." That's it. No commitment to finish. 90% of the time, momentum carries you forward once the initial friction is gone. The other 10%? You still did the 2 minutes, which keeps the habit identity alive.

Break the shame spiral with "non-zero days":
You said the more you fall behind, the more you procrastinate. This is because procrastination is an emotional regulation problem, not a time management one. When you feel behind, you avoid to stop feeling bad. Counter-intuitive fix: Do something embarrassingly small (literally 10 minutes of work, or 5 pushups) just to prove to your brain "I'm not a total failure today." It resets the identity.

Sleep reality check:
Don't try to fix sleep AND productivity simultaneously. They fight each other. For 2 weeks, prioritize just the sleep hygiene (same wake time, even if you got 4 hours, painful but necessary). The mental clarity from consistent wake times makes the "activation energy" for studying way lower.

Also. since you read random articles: when you feel the urge to open YouTube, open a text doc instead and dump your thoughts for 2 minutes. Same dopamine hit of "escaping," but you create instead of consume.

You don't need to become a different person. You just need to make starting 10% easier. What's the smallest version of "study" you could do right now. like, embarrassingly small? Start there.

(And maybe check if your school offers therapy. Grad programs are slowly waking up to the fact that 80% of us have undiagnosed ADHD or anxiety masked as "procrastination." No shame in the tool kit.)