Weird straining feeling at the back of testicles and anus

Starting off, I am a 17 year old male just to clairify. Anyways, about two days ago, I woke up and started my day off as usual. However, when I went to urinate, it felt really weird as if I pulled something inside of my anus or something. I didn't really think much of it until I tried to poop. When I tried, I noticed that it felt even weirder when I was pushing just a tad bit. it feels like something has been pulled or something is pushing up against something and it makes me feel really uncomfortable. When pooping, however, it has a slight pain added with it as well. It doesn't really bother me until I start pushing just a little bit. When I do, I notice it. I also noticed that when I sneeze, I can feel it. It really feels weird inside the area where the anus and scrotum meet.

PS. I ran a 5K race the day before it started. I'm not sure if that has anything to do with it!