BF (M22) is abroad for family reunion, doesn't call me (F22) anymore

I'm having a hard time because my boyfriend doesn't call me anymore at least once a day. We have a 14-hour time difference (PH - US IL) and he's staying for 3 months there. Prior to flying out, we made a promise to update each other daily and call at least once a day, even for quick good night calls, since I know that he will be very busy with making up lost family time. He does send me pictures and videos, to which I make follow-up questions/silly little replies, but he does not respond to my photos and videos that way. He will just go on to say they've arrived home and they'll sleep because of a long day. I just brush it off because I want to be understanding, knowing how much he missed and yearned for this time with his (immigrated) family members there after five years. I was content with our set-up mainly because our good night/mornings calls albeit quick, and I'm also occupied with school work.

One month in, the calls have stopped coming in, nor are there any video call/call attempts in our conversations when I wake up. It's around 4 pm-5 pm there when I wake up. He apologized for the lack of it though, saying that there's just so much to catch up on with his family and that he misses me every day too. I completely understand him, but I still miss his voice and our calls. I'm just crying because I don't want to demand too much in this crucial time for him, but I also don't want to keep having these dry conversations with my boyfriend.

We still message every day, even if we cannot reply immediately (specifically 4 or 5 hours after)since the other will be asleep when the other wakes up. What do I say to him to let my emotional needs be heard without being demanding and sounding selfish? I simply cannot endure our lack of calls and I tend to shut down altogether with overthinking if this cannot be resolved.

We're already 2 years in and have been very close and affectionate back home. I miss him so much; we're practically inseparable when we're together. Might I add that he isn't interested in any intimate online exchanges, so that's not an option to keep the connection alive. We never talked about it.