grievance grief

So, I might be filing a grievance with my union about some bullshit that happened at work. I've never had to do anything like this before, I've never been in a union. I'm quite nervous about doing it. I'm pretty sure that I dont want to go back to the job, but I'm afraid that after filing a grievance I won't be able to get a reference from my supervisor, and this job looks good on my resume. I feel sick to my stomach.