No one taught me how to study and I struggled for a long time too. Universities are getting better at it, but high schools still aren't great in my experience. It is worth spending some time reading about how to study well. It pays off to spend a few hours studying about how to study, and then all studying will take half the time and stick better.
Learning scientists have some fantastic resources that really helped me. Their advice can take any form that works for you: make notes, make flash cards, learn and try to teach your group of friends, make exam questions for your friends.
It is important to see when you are not using these strategies. Understanding a topic and making notes yourself is one thing. Just seeing something online and copying it directly is absolutely not the same. Understanding a topic and teaching it to friends is good, just hanging out to waste time and skim through material and skip the parts you didn't retain is no good.
The other thing to get around procrastination is to plan out so you know what you're going to be studying. This makes is more manageable than thinking in your mind "I need to do all of physics". Instead it becomes "of I could just read the 1st law of thermodynamics today", then it's a lot less of a scary mountain to climb. The school syllabus maps out your learning for you.
Part of the challenge is getting your foot in the door. If you're struggling to start then start with something you can face without scaring you. "I'm going to read this specific topic for 20 mim today" is a lot less likely to scare you away than "I need to study for 8 hours today". The process builds on itself. Once you start, you'll find it's not scary and easy to carry on. Once you know a couple of things and build on that to learn the next thing, then it is quite satisfying for it all to start making sense.
Good luck. It's not easy. But intelligence you're born with really doesn't matter. The only thing that matters is if you're willing to work. There's no such thing as people who study 30 min and get straight A's. This is a myth people like to propogate to make it look like innate genius..... It's bullshit.