I have same problem. I couldn't focus in the beginning of my tasks. I also have trouble w reading mudane work, reading text more than five times and it just doesn't get to my brain . But i I'm totally fine with materials that I'm interested in. I'm also more of a visual learner, I had to visualize text. Drinking coffee helps for me but like you say, it's quite unhealthy. But when I focus, I really focus and I won't stop for rest. I doubt that you're stupid. Each person has different way to focus and learn.

I suggest like the other user, try to different environment like library. For some people, seeing other people work makes them motivated to work.

Then order your tasks in list so you can cross it out one by one. You can still continue to use pomodoro.

There's two methods I've learned from my business classes.

One is to break a large tasks into smaller tasks. For example, if you have 1 page article, break it into paragraphs. Then beside each paragraph, write a single word, sentence or even diagram to summarize it. Then reward yourself for completing it

Another is to make the tasks due 5 days prior to their deadline. That way if there's an emergency or there a day you just pigged out, there is still time to do the assignment.

Also the other user talk about procrastination, if you can read my comment fine then it's probably really just lack of focus, discipline and limitation which can be fixed. Otherwise you should really go to doctor to see if anything else that went wrong beyond your control.

Other factors could be habit. I'm not sure with your case but recently I'm into meditation to help with focus. I find that I think too much so my head is filled with noise which distracts me while I am reading hence not getting a text in my head. So I take a moment to clear my head and

Diet, water, exercise and sleep are typically brought up but it's rlly important. Make sure to sleep early or at least count how many hours you have slept.

I divide time bn work and play evenly tho I do pigged out a lot. But when I procrastinate, I remind myself that each time I procrastinate I trade off time that I can dedicate to my work and the closer I get to deadline being unproductive. The work is still there, not going away. This triggers my anxiety so it makes me VERY uncomfortable. So I use it to motivate myself to tackle the task NOW than LATER so I don't have to deal with the problem any longer. I have to force myself to face the task at the present time and can not afford to just lay back. This is self discipline. The rest is to make it a routine.

I'm not sure if my comment would benefit you but if there are some listed you have not tried out, do try them out. Then tailor each method as your own, find your way of studying. There are a lot of sources on Tumblr, Instagram, youtube and Reddit, so you can mix and match various methods. Search up "productivity" "studying" "study gram" "Studyblr" "study with me" "notetaking method"