is my mom right to be mad?

short story shorter, my moms anniversary with my (19) step dad is today. i told her happy anniversary in person, but i couldn’t afford any gifts since i’m a broke college kid.

she yelled at me for five minutes about no gifts and then became irate that i didn’t also post it on facebook. i told her doing things in person meant more to me, and she said as her only child i am selfish and wicked for not posting a status about it. now she will not speak to me, and when she occasionally does its

“i’m going to the store, not that you even care.”