You can reach B1 Dutch before your integration deadline, but it requires a focused, consistent plan rather than just more exposure. Your current mix of tutor, Babbel, boyfriend practice, and Dutch shows is a good foundation, but the forgetting you describe suggests you need more active recall and spaced repetition. Three years is enough time if you study strategically, not just passively.
First, accept that forgetting is normal. Language learning is not linear; it is a spiral. You will revisit the same grammar and vocabulary many times before it sticks. The key is to make your review systematic. After each lesson, create flashcards for new words and phrases. Use a spaced repetition system (paper or app) to review them at increasing intervals. This directly addresses the "forget previous lessons" problem.
Second, shift from input to output. Watching Dutch shows and listening to your boyfriend is valuable, but B1 exams test speaking, writing, reading, and listening. You need to produce Dutch actively. Speak with your boyfriend for 15 minutes daily, but ask him to correct you gently and note recurring mistakes. Write short paragraphs about your day and have your tutor correct them. This forces your brain to retrieve words, which strengthens memory far more than recognition.
Third, align your study with the exam. Find out exactly which exam you need (for example, the civic integration exam or a state exam) and get sample papers. Practice under timed conditions. This will show you which skills are weakest. Many learners underestimate the writing and speaking components. If your tutor is not familiar with the exam format, consider a short course specifically for exam preparation. You do not need to abandon Babbel, but use it as a supplement, not the core.
Fourth, manage stress and time. Almost a year has passed, but you still have two years. That is plenty if you study 30 to 60 minutes daily with one longer session weekly. Track your progress monthly with a simple checklist: new words learned, speaking minutes, practice tests taken. Celebrate small wins. Stress narrows your focus and makes learning harder, so protect your sleep and take breaks.
Finally, be honest about your level. Take a free online placement test or ask your tutor for a CEFR assessment. If you are at A2 now, B1 is achievable in 12 to 18 months of consistent effort. If you are still at A1, you may need to increase study time or consider an intensive course. Dutch Fluency is one concept, but the real key is daily, active practice. You are not behind yet, but you do need a plan that targets your weak spots. Start today by reviewing yesterday's lesson with flashcards, then speak for 10 minutes without switching to English. Small, regular steps will get you there.