I'm like, "The whole point is I'm trying to get off that plan! They aren't the ones I need to talk to!"
Mom and I were talking about this, and she suggested I ask at RHA and see if they'd let me add on to their group plan. This was such an obvious solution that I felt dumb for not thinking of it sooner. Since I don't work full-time, I always figured I wouldn't qualify, but it never hurts to ask. So I explained the situation to my boss, and lo and behold, RHA was willing to let me add on. Hooray! It's still not the cheapest health insurance - I have to cough up $150 per paycheck, which SUCKS - but it's a much better rate than I was paying to the school district, and it's a better deal than I would have gotten on an individual plan.