Nobody can answer that. Not because the question is silly, but because it is a question about you, and the answer is not in you. It is in the chat.
Ask a different question: what did he mean? That one has an answer, and most of the time the next 3 messages already hold it.
Free to try. We never store your chats.
Your friend said you are overthinking. The internet said red flag. You still do not know, and that makes sense. Both of them answered "am I overreacting to his text" without reading the text.
Without the thread, all anyone has is how you sound when you ask. Worried sounds like overthinking to one person and like a warning to another. That is 2 opinions about a stranger, and you end up where you started.
Take a short line like "it's not that deep." Read alone, it stings, and you can read it all night. Now look at what came after it.
If those are there, the short line was a bad moment, not the message. The message is that he came back. Those are 3 things he did, not 3 things you are hoping for.
If nothing came after it, and the topic just closed, then your feeling is picking up on something real. That is not overreacting. That is reading the chat.
How he normally talks to you. If he is short with everyone about everything, a short line is his normal. If he usually answers you with care, then the brush-off is the part that changed, and noticing a change is not being too sensitive.
1 night or a pattern. 1 cold reply in a hard week is 1 point. The same brush-off every time you bring up something that matters is a pattern. When people ask "am I overreacting in my relationship," they are often asking about that. Look back over weeks, not hours.
Answer his last message, not his first. If he already came back and offered tonight, do not reopen "it's not that deep" to prove it hurt. He took it back. Let that count.
Something like: ok, tonight works. i'll tell you what stuck with me
That takes the time he picked, keeps the real topic on the table, and does not turn it into a fight over text. The talk you wanted still happens. It just happens tonight, in full sentences.
If you are on your 4th draft at 1am, the text you send will be about the night you had, not about what he said. It can wait until you have slept.
If he asked for a break from the topic, give it. If he blocked you or told you to stop contacting him, that is not something to read your way around. Do not push contact.
Sending nothing today is a normal result. It does not mean you lost the argument. The chat will still be there tomorrow, and so will the question of what he meant.
You paste the whole chat, not 1 line. It reads the short text against what he did right after and against how he usually talks to you, so you get "what did he mean" instead of a verdict on you.
Then it writes the reply back in 4 tones, and tells you if the better move today is to wait instead of sending anything.
Try it on your conversation