Cold sores 😭 What should I apply?

Cold sores 😭 What should I apply?

My lips were itchy, and then blisters formed on the top and bottom.

I wonder if it's because I'm tired or if my immune system has weakened.

It seems like my skin is reacting immediately😭

I don't have any ointment to apply to my lips, so I'm wondering if I should just use whatever the pharmacy gives me.

Vaseline wouldn't work, right?