I have never had white spots on my lips,but thats not to say it cant happen anxiety comes with so many different things,i would go to the doctors to get them checked out if you had oral sex,good luck
Normally anxiety doesnt cause white spots. However stress can cause cold sores to come out. Is that what it looked like? If you had unprotected oral sex I would go and see your doctor and let them know, they may be able to do a swab.