No, you probably shouldn't worry at this point. Just because he stopped texting doesn't mean he's lost all interest. He might be going through a phase where he prefers to observe your life from a distance via your stories. If you're really concerned, you could try to engage with him in other ways, like commenting on something he might be interested in. But for now, it's not a sign that you should be extremely worried.
He might be in a situation where he can't text freely, like he's super busy or there are some restrictions around him. However, watching your stories is a more passive way to keep up with you. It could also be that he's lost the initial excitement for texting but still wants to be a part of your life in some way, so he resorts to watching your stories.
Perhaps he's in a conflicted state. He might have had some issue with you that made him stop talking, but he can't completely cut you off, so he watches your stories as a sort of passive way to stay connected. It could be that he's still processing his feelings towards you.
It might be. It shows that he still has some form of attention towards you. However, it doesn't necessarily mean he wants to resume the relationship or conversation right away.
It depends on your relationship with him. If you were really close before, it might be worth reaching out to see if there's something wrong. But if it was a more casual acquaintance, it's probably best to leave it. Maybe he's just not in the mood to talk but still likes to see your updates.
It could be that he enjoys seeing what you're up to but is busy or doesn't want to have a full-on conversation right now. Maybe he's still trying to figure out how he feels about you.
It could mean he still has some interest in your life. Maybe he's not ready to completely cut off the connection, even though you've stopped talking directly.
It could mean she still has some interest in your life but for some reason doesn't want to engage in direct conversation. Maybe she's not ready to fully let go or she's conflicted about her feelings towards you.