Calling all Cat Experts. Please help. I believe my cat, Kitty is h**** and I don’t know what to do.

I have never had a cat before, strictly dogs. And now Kitty is purring like crazy and rolling around on the floor sticking her b*** in the air. At first I thought she just wanted to be pet. So I pet her. Then she wanted me to pet her b***. So I pet her b***, but now she’s pushing her b*** on me and shes wet! WTF, Don’t rub that on me!!
I have no idea what to do. I stopped petting her but now she’s just pur meowing at me to ‘pet’ her. E___E I don’t think I have ever felt so uncomfortable with a cat before.

She is young, I found her in a bush a long while back as it was raining so I couldn’t just leave her. She is not fixed and maybe about 7 months old now. Is she going to start her first period? Do I need a diaper for her?! How long will she be acting this way? (All day so far, yes ALL DAY.) Does she need medicine or should I just give her a back massage to calm her? Is catnip something that helps relieve the pain?

I just need advice as to what is happening and what to do if anything.

Signed,
– A very confused dog person.