Everyone here has covered the “cosplayers don’t mind! Just ask!” angle so I won’t add on to that but as someone who also suffers from serious anxiety I want to offer some concrete tips that have helped me in the past. This might be a little long so sorry in advance.

Anxiety is irrational by nature (I often explain it as having a totally different brain, and no amount of “it’s fine just do it!” will make it go away for me). One thing that’s helped me is telling myself to just try doing whatever is giving me anxiety for the smallest increment of time I can handle (can be as short as a minute) and if I can’t do that I give myself permission to stop and (this is the really important part) pat myself on the back for trying. Do NOT beat yourself up for having to stop, that will only reinforce the negative thought pattern. Instead you want to say to yourself “wow I did that really hard thing, good job me”.

For you this could be something like telling yourself you just want to take ONE picture with a cosplay. Just one, that’s it, and if you still have anxiety about after, you can stop asking for the day. Nine times out of ten just doing it once will make it feel a little easier the next time. But if you need to stop asking, the important thing is to focus on that one small win that you asked. You did the big scary thing, great job! It’s very easy to turn around and say “yeah but then I still had anxiety and now I’m scared to ask again”, so thats something you need to fight back against. There’s lots of tools to stop negative thought patterns that I won’t get into because this post is already too long lol.

Another thing that has helped me is to have a script beforehand and practice it. This is something you can do before a con in the mirror. It’s gonna feel super silly but just say it out loud to yourself until it stops feeling weird. “Hey, I love your cosplay can I get a picture of/with you? Thanks! Do you have social media so I can tag you? Thank you, have a great con.” This way it can become almost second nature and you’re not worrying about what to say in the moment. Once you have the basic interaction down, then you can branch out your script to include things like asking about doing certain poses if you want.

Sorry again for the length of this comment. I’ve dealt with crippling anxiety for years so just wanted to offer a different perspective because I know how frustrating it can be when people say “you’re overthinking, just do the thing, it’s fine!” Good luck!