A Petty Lie I Told My Partner

I feel so ashamed to confess this, but it's something that's been bothering me for weeks. Last month, my partner asked if I wanted to go see a movie together on the night of our anniversary. I didn't want to do anything besides staying in and watching some old favorites at home because I had an essay due soon. But rather than be honest about feeling too busy with schoolwork, I lied and said that we should celebrate by going out somewhere fancy instead. Now I feel terrible about it since my partner seems disappointed that we didn't spend our anniversary together the way I initially wanted to.