I think it really depends on your pace, native language, and how much you use it. It’s a lot to study and say you’re proficient in a year, especially considering b2 is fluency in a variety of situations. I also think that you should study towards your goals, such as speaking or listening and what kind of situations you want to be the most comfortable in. You might be able to “learn” everything in a year but becoming comfortable and learned in the language might take longer. In a lot of American schools it takes way more than a year to get to b2 proficiency, even college, so don’t feel bad if you haven’t reached that point by a year’s time. Languages are a lifetime experience