Why Would a Guy Show Interest in Me, Texts Me Daily, Then Suddenly Stop? Is this a test?

[Jae]

A few nights ago I got a random facebook message from a guy I met in college. I think he might like me because he'd stare a lot in class and go out of his way to talk to me. Anyway, during the fb convo he asked me how I was, if all my time was dedicated to working these days, and suggested that whenever I'm in town I should "hit him up." I recently moved to a different city and no longer attend his university. We exchanged numbers.

For the past few days we've been texting back and forth. He always texts me first, pretty early in the morning. Yesterday morning he texted me around 9:30am and said “good morning!” and continued our convo from the night before.

He texted me last night and I texted him back and ended my msg by saying goodnight, but he hasn't responded since. Totally weird because we've been texting for a couple of days and he always texted first. I worry maybe he's lost interest/isn't into me anymore. I talked a lot about myself in the text convos, mostly because he asked a lot of questions about me. I returned questions, but wonder if maybe I didn't show enough interest and so he's backed off. Maybe I'm just boring, or not how he thought I'd be.

What should I make of his sudden disinterest? Is he testing me? Thanks.

(btw Sorry, I know it sounds like an amateurish question, but I have social anxiety, and no experience with guys so I'm more than a little awkward and unconfident around them.)