First and foremost, your boyfriend is mad at you because he misses you and is now worried that the argument that you had with your parents is going to lead to you choosing not to visit him in Europe.
He is also mad that your parents don’t seem to respect nor value his relationship with you.
This is why he called his relationship with you worthless.
He is simply frustrated at this point.
He doesn’t have access to you as easily as he used to and that isn’t helping him mentally.
He ignored your response to his text message because he is still trying to show you that he is upset.
He will get over that soon and reach out to you.
When he does, it is best to avoid mentioning the argument that you had with your parents or what he said about the relationship.
Instead, just reassure him that you are still coming to visit him and you can’t wait to see him.
Then proceed to talk to him as you normally would.
Ask him fun questions about Europe.
He was previously so excited about you visiting him.
He still is.
He doesn’t truly believe that the relationship is worthless.
He will eventually come around and begin to tell you about all the wonderful stuff he is going to show you when you visit him.