Why Did I Do That?

So I work at this office that's really dull. It’s the kind of place where everyone has a designated mug and they sit in the same spot every day, never deviating from their routine. The coffee machine is always broken on Wednesdays because no one ever calls maintenance until Thursday afternoon when they remember it needs fixing. This week was particularly slow at work, so yesterday I decided to play a little prank. There's this guy named Alex who has been super stressed out lately with his workload and deadlines. We were all joking about how he needed a break but no one ever actually suggested anything concrete. So, I thought maybe doing something silly would lighten the mood. I got some of those colorful foam earplugs you can buy at any dollar store and hid them in Alex's desk drawer along with a note saying 'Take a moment for yourself.' Then, I put his usual coffee mug out on top of his keyboard when he was away from his desk, hoping it would look like someone had just left him a hot cup. Today morning, everyone was whispering and giggling as Alex arrived at work. He pulled the note out and read it in disbelief before finding the foam earplugs. His face went from confusion to utter embarrassment and then he stormed off without speaking to anyone. Now I’m sitting here feeling terrible about what happened because while my intention was good, it backfired terribly on me. Alex is now avoiding everyone at lunch and even avoided talking to me when we crossed paths earlier today. Did I overstep? Or should I just apologize directly or wait for him to come to me first? So, am I the asshole here for trying to help but failing miserably? How do you think I can make things right with Alex without making a huge deal out of it?