Controlling relationship?

My last relationship ended pretty nasty. He disapproved of everything I did, but was particularly set on trying to get me to stop my anime "habit". My family was so upset it ended over my "hobby". I love anime, really I do. But do you think, that we should grow up? No one really understands how much passion I have for it. I just don't know anymore.

If whoever you were with can't agree or acknowledge your interests, seeing them as some obtuse "habit", good riddance. That is, unless your interests are very very uncanny, extreme, isolated and/or are so obsessed to the point where ANYONE can see its not normal as well as negatively affecting your life. But having anime and manga as an interest isn't childish or a sign they need to grow up. Sure there are bound to be people obsessed with anime, manga, and even japanese culture, just as people can be obsessed about anything, but that's different than being interested in something. Unless your interests somehow get in the way of being able to support yourself in a job, college, and etc, there's nothing childish about it. Keep on pursuing your interests and passions while being able to financially support yourself. So if your family or anyone you meet doesn't agree with Japanese cartoons just because they think its childish, they clearly aren't keeping an open-mind or thinking about you.

As someone who used to be a really controlling guy in his younger teens, I can say 100% that its unhealthy. You should be loved and respected for things that represent you at your core, not only by whoever you're dating, but also by your friends. Like AzureTower16 said, criticisms regarding bad habits like alcoholism or drug usage are definitely causes for concern (For people who partake in them), but something as small as your love for Japanese entertainment is just a sign that the other person has a problem accepting you for who you are. Relationships are give and take, and in my opinion, require you to learn to appreciate and engage in your partners hobbies. As a result, if he couldn't cope with your passion, then it probably wasn't going to work out either way. Hopefully he realizes that his controlling ways aren't healthy, and finds it in himself to change his perspective.

I just felt so targeted. As overused as it is, I was wondering if it was a phase. He made me feel just awful about it. But I eventually decided, that I fucking love cosplay. I love anime. And it's not going away, and I never want it to. It's astounding that he even tried to make me choose.

Disagreeing with another person's interests isn't a phase, its a difference in character. A phase would be when you grow as a person when in adolescence. But demeaning others for their different interests or beliefs is a irrational, authoritarian belief. Conflicting beliefs and interests are never an excuse to demean or belittle them and others. Everyone has different beliefs, philosophies, and things they do for fun, and while they may be seen as weird or even wrong to others, as long as that person is happy and is able to live a stable life, what's so wrong with that? Since he did make you choose, good for you that you chose your own interests and passions over pleasing others or staying attached outta pity or fear. People who fail to see others as the individuals they are can only fear and lash out what they don't understand, what they don't like about others, what they can't control in others, and have unrealistic expectations of them. Be proud of yourself, not conflicted.

You were right in ending the relationship if he was trying to control you. You love anime and you love to cosplay. If a guy really cares about you then he should respect you and the things you enjoy even if he does not. Also it seems like he was trying to control more than just your anime habit and that is a prime ingredient for a toxic relationship. Don't worry about you family being upset. They don't understand how much this "hobby" means to you. It is a part of who you are. Don't feel bad or feel like we should give up on it. We all have our passions and if someone does not understand it is not your problem.