2 weeks ago, I stupidly kissed a girl whilst drunk. I did not notice any chancres/sores and I certainly do not have any chancres/sores on my tongue/mouth. Last night I performed cunnilingus on my partner for 2 seconds. Should I be worried that I have given her syphillis? Or is my anxiety taking over? Thank you for your help.

Welcome back to the Forum.  I'm perplexed that this question even occurred to you.  Syphilis is transmitted through direct contact with an infected lesion.  You did not see a lesion, you do not have a lesion, and syphilis is virtually never transmitted through a simple brief kiss.  I believe your anxiety/guilt is getting the best of you.  I would have no concerns following an exposure of the sort you describe, no matter who you kissed.  I would not worry and see no scientific reason for testing.  EWH---