Overcoming Gaps in Front-End Development: Need Advice

I’ve been studying front-end development on my own, starting with HTML, CSS, JavaScript, and some React. I didn’t go too deep into React, and after some time, I realized I need to learn computer science fundamentals. A lot of the resources I found teach these fundamentals using C++, and it seems like it would take me a long time—maybe even up to two years. I’ve been working as a front-end developer for nearly two years now, mainly handling tasks involving HTML, CSS, and basic JavaScript. However, I’ve struggled with tasks that require more advanced logic, like those involving Angular or complex JavaScript.

How can I overcome this gap without starting over with computer science basics? I’m 27 now and don’t want to spend too much time going back to fundamentals. Any advice on how I can improve my skills while building on my existing knowledge?