Frustrations

There aren't many things that are stressing me out lately. I have anxiety, and some things have got me super frustrated lately, but not really stress. I've been in far more stressful jobs than my current one, and besides, this job is one I absolutely adore. God has allowed for me to find something I love, and I am so grateful for it.
My current anxiety is mainly centered around new experiences and new responsibilities at work, and are largely just a normal part of my life with Aspergers (an autosm spectrum disorder).

My frustrations however are people-related.
See, I am an avid musician - I've been playing music since i was tiny and it is one of my absolute passions. I'm part of the church's worship team, and I feel i can bring a lot to the table since i play a lot of instruments. But for some reason the 'leader' doesn't seem to see it that way. She thinks that my being versatile means I'm not particularly good at any one instrument but rather that i dabble a bit in all of them. Trust me, this is not the case. I've made it clear to her that, for example, I have a grade 5 level in guitar and also in music theory and that I've been playing guitar for 15 or so years. But still they don't include me when it is obvious that the band lacks in certain areas.

I don't know how to handle frustrations like this without just completely backing out of the group.

Why is it that i cant have more than one aspect of my life going well at one time?