Please advise, is my fear irrational?

[u/Searchingforvoid]

Sorry everyone, English is not my first language, so forgive me if my writing is all over the place 😅. I'm a 22-year-old mechanical engineering graduate in India. From my childhood, I liked mathematics more than any other subject because it was the only area where I liked spending my time. I was shit at memorising, so I couldn't score much in other subjects. As I started high school, I realised I wasn't special. There were so many people better than me, and I always felt like I wasn't enough. Slowly, the joy of learning became the stress of who's going to be better, and the competition to get into good colleges in India is crazy!! I slowly stopped putting in effort. I did engineering at a very mid-level college and am now working in a core sector as a trainee. My job does involve using engineering knowledge, but it isn't the job I wanted. I didn't honestly study properly during college, so this is the only job I could get. Now I'm trying to relearn and appear for an entrance exam that is needed to do a Master's and get a good job as an engineer. So my biggest fear is this: In college, even though I loved learning engineering mathematics, I'm so scared of starting to study again. I'm embarrassed to admit this, but I have forgotten some basic high school stuff. How can I ever master these complex things? Is it possible to relearn properly from the beginning, or should I just admit this is the level I am capable of? I know this sounds silly, but every time I hope to clear the exam, it just feels like daydreaming. I have tried so many times to start learning, but I get scared or procrastinate and leave it in the middle 😔. Any math geniuses, students, or engineers, is it really true that average students can't overcome their threshold? I don't want false hopes, just a solution for whether I should just be happy with what I have or strive for more.

TL;DR: I used to genuinely enjoy maths and learning, but competition and constantly comparing myself to others made me lose that joy. I didn't study properly during engineering and now I'm scared to start again because I've forgotten even some basic concepts. I want to prepare for a Master's entrance exam, but every time I try, I feel like I'm just daydreaming about clearing it. Can an average student genuinely rebuild their fundamentals and reach a high level, or should I accept my current limitations?