What part of your dissertation is actually slowing you down right now?

What part of your dissertation is actually slowing you down right now?I’ve been seeing a lot of posts about dissertation stress lately and it made me curious what the real bottleneck is for most people. Is it:

• finding enough sources?
• turning research into actual writing?
• structuring chapters?
• staying focused long enough to make progress?
• or just motivation in general?

From what I’ve noticed, a lot of students like their topic but get stuck somewhere in the process and it slows everything down. I’m really interested in hearing what stage people are at and what’s been the hardest part so far.