When a fearful avoidant deactivates

Hello,
I was in the early stages of dealing with a fa who leans ap until he deactivated. Everything was moving fast with us so I can see how that could of triggered and was he started to slowly deactivate I got trigged and my ap side started to show it was nothing over the extreme. He deactivated for 2-3 days twice in those 2 months and both times I sent him a message he responded back almost immediately. The first time he wanted to make sure he wasn’t the only one initiating conversation and the second time he said he thought I was mad based off my reply so he didn’t respond. (I’m not sure if these were test) I let him know that wasn’t the case and he apologized. The last two serious talks we had. He explained that he didn’t understand why or believe that I liked him because he feels unworthy and he things I’ll leave him. I tried to get him to go deeper about feeling unworthy but nothing. I also try my best to give him reassurance. A few weeks later he was still deactivated and being inconsistent so I asked did he feel like he was getting attached he said a little but things have faded because he doesn’t have much time because of his new job. A few days later he went silent and deactivated I let him be he wasn’t on the social media app we follow each other on at all. I let him be about 3-4 weeks later I sent a follow up message saying that I’m checking in and hope he was okay. A month later so last week he finally read both messages and never replied. I was instantly sad and disappointed but didn’t react and haven’t reacted. At this point I’m kind of stuck because I’m not sure what’s going on. He has shown signs of him being depressed and suffering from mental illness. I just try my best to not think of it that much but it’s hard I want to let him know that I’m here and I care but I don’t want to push him away.