My (23F) 23 M bf has gone silent, I’m confused?

Me and my LDR boyfriend have been dating 8 months, and I thought it'd been going great. We'd been talking everyday and I got a ticket to fly out to see him in two months. However, we had planned a call this week and I rearranged my schedule to make sure l was available and he didn't end up calling. Also I had sent him a new years gift, and he said he would get me one but hadn't gotten the chance to buy one at the time which I didn't mind at all, and he said he'd send it to me when he got the chance. About three days ago I mentioned these two things and just said something along the lines of me making the time for the call and him not calling bothering me, and if he was still planning on sending me the new years gift he mentioned. He has alot of family stuff and work stuff going on right now so I said he could take his time replying, and he responded with “I’m so sorry, I'll respond properly later" but it's been three days now since his message. We were totally fine and happy right before I sent that message. I haven't heard anything since his message and I messaged him yesterday if he was ok since it's been a day or two. Prior to this, he's always talked and texted daily and called when possible. Is he ghosting me or just feeling uncomfortable and unsure as to what to say about being confronted with what I brought up? He's been amazing other than that but l'm a little confused. He viewed my Instagram story and opened some meme I sent him on insta too, is he just avoiding a possibly uncomfortable conversation? For context we're both from and living in different countries right now so idk if it's a cultural difference but l'm feeling a bit confused :( i know he has depression but he’s been treated for it and hasn’t acted like this before so im really lost. I didn't message him again after I sent my message asking if he was ok, which I think is the right thing to do but l'm not sure. Any advice?