I need tips on how to watch lectures faster.

I've finally gotten my meds mostly right and I've been able to mostly stay on top of uni. Now that assignments and exams have come around I am really struggling with the workload.

I have found that I spend about 4 hours watching a 2 hour lecture on 2x speed. I feel the need to get every single detail out of the lecture, and I also struggle with keeping focus without my mind drifting off so I often need to rewind.

I study biochemistry so it is quite important that I get a lot of details out of my lectures. I annotate the slides on my iPad which are mostly just metabolic pathways with no explanation so I spend time writing explanations from the lectures but it's just taking too long.

I'll spend 5-7 hours per day doing lectures and I find I have no time for any other study. I find I become pretty useless after 8pm so it's hard to extend that time unless I am studying with someone else.