yeast infection?

So I had sex with someone for the first time since I ended my relationship with my boyfriend, I met this guy at an auto store and we clicked we talked for a while then I went to his house so we could hang out and we started kissing. I've never had sex with anyone I wasn't dating and was scared shitless but did it anyway...it was frigging amazing! Ive never had sex like that before! And I've never had oral sex before, my ex boyfriend thought it was disgusting to go down on a woman but this guy was not shy at all. Anyway short story long the next few days there was a smell, at first I thought it was just that sex smell but shouldn't that go away after a few days now I'm a little itchy down under and have this giant pimple on the lip of my vag, I'm not sure if I should go to the doctor  but I'm wondering is it super serious or am I just over thinking things or do I have a yeast infection because I looked it up online and that's what it's looking like