I think I can understand at least a little how you feel. I struggle with a second language. I can get around okay, but not have a real, meaningful conversation. It is a distinct disadvantage when I travel to that country.
That being said, it does sound to me that you are giving up way too easily. Studies show that adults can and do learn new languages. You have the distinct advantage of having heard and spoken your native language a little bit. That means you are familiar with its sounds. You probably won’t have an English accent once you learn more of the language.
The project of actually engaging in the discipline required to learn the language may seem overwhelming to you. I think that may be why you are blaming your parents instead of getting busy yourself. But blaming them won’t help. Once you’ve established that they “failed you”, you still won’t know the language.
By the way: I don’t think they failed you by not anticipating a negative effect that only speaking English would have on you. While you were growing up, they were probably doing what they thought was best for your future.
Where did you get the idea that “no one will teach a language you’re supposed to know”? That’s false. Even if there are no formal lessons available, there are tutors, Youtube videos, books, audio programs for purchase, and internet programs, etc. Get yourself a dictionary and learn 10 new words a day. Immerse yourself in the language. Go to movies and watch TV shows that are in your native language. Hang out in places where most of the people speak it. Go shopping in markets where you need your native language to get along. You could even ask your parents or adult relatives to work with you for a few hours every week to get you fluent. People are usually very interested in teaching an enthusiastic and willing student.
You are young and smart. It is very likely that you can become fluent in a year or two if you really apply yourself. If you don’t apply yourself, you’ll still be in the same situation 2 years from now. It’s your choice.
I wish you well.