Therapy helps friend. I envy you. Music is my passion, and I've lost the will to play it. At least for now. I just can't play music anymore. Just after all the shit I've been through recently with my relationship, i'm just numb. I wish I could have it as an outlet again.
But I can tell you, therapy has helped me quite a bit. Just being able to talk to someone. And yeah, it's very hard trying to do this on your own. It really hurts when you have someone not care about you anymore. Like when you care so much about them, and then they don't.
My situation wasn't 1:1 yours. Because I think the other person did care still, it's just we are in different places. And there is something about them as a person, that I don't understand. Where they just don't put the same effort or care the same as me (for whatever reason). I guess the end result is the same, both of us are hurting because we've I. have that hole since that person is not in our life. II. The pain of caring so much about someone, and not having it returned.
It really sucks. I wish I could give you advice. And say, you will just meet someone else. You will meet someone else. I'll meet someone else. Doesn't change the pain. Because if you really cared about this person, it's like THAT specific kind of happiness, is something you won't get back. You will find new happiness. But not that specific one. And that is what is really hard. Still, if you ever need any support, just let me know. I dunno. I think we are kind of going through the same thing.
EDIT: How far are you into your masters? Sometimes it just makes sense to complete a degree, and then just apply for other fields later on. I've known people that could get hired at other jobs, just because jobs/fields don't always hire people based on the degree matching the field. The pedigree of having a masters is alone, really good on your resume (even if it doesn't match what you want to do). So if you are almost done with your masters, it might just make sense to finish it.
But if you are just starting out, then there is nothing wrong with switching. Do what your heart tells you. You only have this one life. So make the best of it. Do what is right for you.