Is he losing interest or am I overthinking?

i recently began talking to a guy I've been off and on with for 3 years. I finally confessed my feelings and he agreed we should both get to know each other a little better before dating. So we've been texting almost every day. Last night, I even watched a movie he told me to watch and then we had a super deep conversation about it afterwards. So today I texted him and he was gaming so I wasn't getting texted as regularly as usual. But something felt a little different because he typically drops everything when I start a conversation. Part of me thinks he's just gotten comfortable with me (which isn't too soon since we've been very close friends before) but the other part is wondering why he didn't at least try to respond faster, or say he was going to bed. i understand I am an overthinker and relationships are supposed to go up and down a little, but I want to make sure.

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Also I forgot to add, this guy is very shy and probably more nervous than I am to talk. He puts in a lot of effort to talk to me and I can tell he's definitely going out of his comfort zone. He is not awkward when we're talking, but he struggles to begin a conversation and doesn't really know how to communicate.
Is he losing interest or am I overthinking?
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