I feel like a complete idiot for not checking before. Honestly, I thought for sure I was making what I was promised, but I just did the math out of curiosity after 6 months and found that it's $9,000 less than my offer. When I brought it up with HR, I was told that my offer letter says the amount I'm being paid. I told her I had a separate agreement that the stipends on top of my base pay were to get me to the target. I received no response. I've been ruminating over this since and it's devastating. How could I be so stupid? Why didn't I look before signing? Why didn't I raise a red flag before when my boss wasn't yet the worst? I've been miserable in this job since about 3 weeks in, and now find out that I was also lied to about my pay…I'm sick over it.
Moral of the story here, I guess, is EVERYTHING needs to be in writing. Everything.