If you're doing this badly despite putting work in, then the likelihood is that you're not doing the right kind of work. Maths is not really like other subjects - information recall is virtually worthless here without the understanding and the ability to apply it. Learning methods takes a different type of revision to learning facts. If you know those methods, then you need to practice them. Do past paper questions until you get totally bored because you've seen almost everything before but with different numbers. If you don't know the methods, you need to relearn them by going back to examples, videos, your teacher etc. The basics are important and if you don't master the first year, the second will be even more brutal than it is normally.