"Communication breakdown...it's always the same."
As stated above a few times, I think it's prolly from lack of attention (as she sees it), or your finances really are the issue. Money is the #1 cause of divorce in America, so regardless of the situation of income, you gotta be on the same page with finances, by sharing goals, budgets, and responsibilities.
But as you said you broke even on the exchange of units, I gotta lean towards the attention aspect. If you don't think she understands the depth of your passion for music, try and convey it to her. You might even try inviting her to become more involved in your music, even if just asking of her opinions. If she's not too interested in music anyways, just set aside personal time where she knows she's guaranteed your attention. Certain nights of the week, or certain times of the day would be "hang out" time. Conversely you would have set aside "play" time.
So yeah, it's a 2 way street...you gotta be clear how you feel, and she can't just get mad and not talk to you for days...sorry, but that's just childish.