Bump by lip

So I've been having a bad breakout of acne for like two weeks. But last Sunday I felt a tiny bump under my skin that hurt for like two days. I kept applying acne spot cream with no help then Wednesday I applied toothpaste to dry a couple pimples out including this bump. It made my skin flake. But I've just started seeing a guy and we've kissed plenty of times. Never seen any bumps by his mouth. I'm freaking out bc one friend said it looks like a cold sore. It's a little red but has had no weeping from it and has gotten a little smaller. Doesn't hurt, doesn't itch it's just there. What do you guys think?