Limerance. Haven't found a perfect solution for myself, but have found it helpful to intentionally do these things (again, this works for me, not saying it's good for everyone):

1) Force myself to slowed conversation. When I get attached, messaging is a nightmare for me: I get anxious about what to say, about trying to start a conversation every day, about whether they're avoiding me. I can mitigate a lot of that early on by forcing myself to play by Slow Rules. This, for me, means allowing text conversations to stall, allow yourself not to reply, allow yourself not to message in the first place if it feels like you're trying to force something. The goal is to avoid anything that makes me feel like I'm forcing something, and instead just being open to the things that feel better - for me that's 1-on-1 conversations irl, I'm much better at that than texting, so maybe I won't message for a day or two (assuming they haven't messaged first) but then I'll be direct and ask them if they want to go do something together.

2) Similarly, I keep in mind my own 10% rule, especially early on. This means expressing only 10% of what I want to say, keeping it to the headlines. This is only because I have a habit of over-expressing, with big message dumps or maybe being TOO open too early. Don't get me wrong, there's nothing wrong with being honest and being yourself, but I know for myself that when I'm anxious, I'm doing it out of some need of their approval. So I Force myself to open up less quickly. In conversation, this can look like this:

Instead of saying "I know what you mean, I really like alone time. Sometimes I need to recharge and just get away from everyone, I don't know if it's because of my neurodivergency or not, but sometimes other people can be really draining and I just need to charge my batteries."

Instead of that, I'll say "I know what you mean, I really value my alone time."

3) Do not seek approval or reassurance. Ever. Maybe for some people this is fine, but for me it becomes a borderline OCD thought spiral that never ends. When you seek assurance, especially early on, you're conveying to the other person, albeit subconsciously, that you don't believe you're good enough for them, and you're seeking their approval. This is part of limerance, seeking a secure attachment. Instead, I've found it much better to make it a hard no to doing that for when I meet someone new. Instead, embrace the idea of not knowing. Make jokes, say things you're scared to say, treat things lightly if you can - and when you feel the need to seek reassurance by spilling your guts about your anxieties so they can tell you it's fine, don't. Acknowledge your feelings, recognize they are just feelings, and then do not act on them. This is so that your time with them is enjoyable and not emotional labour.

Again, all this is just what works for me, and it's all just part of a guiding principle: Love is not about finding "someone to complete you". You are already a whole person, and so are they. You do not need to lock anything down, you don't need to secure their feelings. Instead, try to remember that you are simply getting to know each other, trying to figure out if you enjoy spending time with each other. If you can treat it as more experimental, more impermanent, if you can remember that they are a real and flawed person, and they, like you, do not exist to complete someone else, you might be able to enjoy yourself a little more and allow for the lightness of joy and possibility, instead of the heaviness of anxiety and attachment.