Lumps in ??? Please help?

I have multiple pea-sized lumps behind my left testicle. They are very uncomfortable, and you can tell that the left side of the looks bigger than the right side. They aren't on the testicle, and they aren't hydroceles or varicoceles, I know that. I do have some symtems of testicular cancer, but the lumps I am pretty sure aren't on the testicle... Low back pain, fatigue, I think the lymph node on the left side of my groin is inflamed also. I don't know whats goin on... I am 15 years old, not ually active at all. Help please???