So Scared! Please help!

I finally had my period after 2 months of not having it. It was very strange because my cycle was very on time. But I finally had my period and everything was normal. Yesterday though, I was on my last day of my period and I went to the bathroom to change my pad out and there was a awful very foul smell! I've never smelled like this before. I thought maybe I just didn't change out my pad enough so I just cleaned up and put a new one in my underwear. But then today I noticed that even though my period had ended.. The smell was still there. Not as strong but still there. And then....... I thought maybe I left a tampon up there. Maybe that was the smell. I've never accidentally left one up there but who knows.... So I decided to feel up there for it by just stick a finger in and I'm not kidding when I say i felt so tight and then I automatically felt a lump kinda like a couple inches in the top where like my gspot is. It's fleshy and hard. My vagina has NEVER felt like this. Idk what to do. I'm so scared that maybe I have a prolapse or cancer or something... Please help...