What To Do If Having Pain In The Thigh, Groin After Running Cross Country?

I run cross country for my school, and I have had been sore/in pain for the last bit of the season, but I ignored it because I wanted to finish the season,



Now it's over and i want to keep running to stay in shape for next year but I honestly can't because it hurts too much. It's only on my left side... I feel like I pulled a muscle in my butt and aches at night and when I sleep, and then where my thigh attaches, kind of in my groin area, it's really sore and when I put weight on it feels like something is ripping. And then all down the inside of my thing hurts. Any advice?