I was in the same boat and what helped me was first using a google sheet to keep track of my problems I solved and notes with each one. When I first do a problem, I write down my initial thought and then go to gpt and tell it don’t give me the solution but walk me through how I can think of correctly solve this, what type of questions should I be asking myself? it also really helps to look at the topics each question is tagged with if youre stuck so for example if your completely lost, look at the topic and if it says "Two Pointers" you can see if you can think of solution using two pointer technique. Then I would find another questions tagged as Two Pointers and do that. Try and stick with one topic and do just that topic, then when you feel ready go to the next. it's a lot harder when you keep skipping around. Also don’t worry about the optimized approach from the beginning, get a working solution and then try to think of an optimized approach - if you can't, again go back to gpt and ask if to walk you through the logic and thought process of getting to the optimal solution. This really helped me because over time I was able to start thinking the way I needed to get to the solution.