I know what you mean about being bilingual. You can say it the way I put above, or you could say, “I want to be fluent in English,” or “I want to be bilingual in English and (other language name).” With your second sentence, you could say, “I sometimes struggle to show myself fully,” or “I struggle to show how I really feel,” or “I struggle to say what I’m really thinking,” whatever applies best. In the fourth sentence, you could say “be in love” or “feel loved.”