From B2 to C1

Recently, I've noticed that my level of English isn't so perfect as I thought before. I hardly can find words to express my ideas, I always forget something and need help of dictionary. My vocabulary isn't rich and even in grammar I make stupid mistakes, especially in speech. So, my first goal is to enrich my vocabulary and train grammar, then oral skills, academic writing and after that make attempts to get ready for any official language exam.