That all cows eat grass thing is part of the problem. It means that every note you read has to start with a process of identification that is time inefficient. You need to start with one note you can identify every time. Doesn't actually matter which one. Then add a second. A third. You need to see C not have to work it out. Imagine trying to identify a word by going ABCDEFGHIJ etc every time. You recognise A and you recognise G. Then add one accidental. Then two. And three. Simultaneously, you read rhythms. Quarter notes. Quarter note rests. Mix them up. Triplets. Sixteenths. It's not that hard, it just needs systematic attention.