Razor burns or STD?

So I shaved myself recently. And like few days after I have my period and also had sex.

My vagina starts to burn when I pee. There are small red bumps and the whole labia minora (opening of my vagina) is swollen. Like it hurts to touch and I can’t even put a pinkie in.

The sex and period made it worse. But I have no idea what caused it.

Anyone experienced the same ? How do u treat it? And how long did it take to heal?