What would cause my testicals and anus to feel like they are on fire burning

You : You need a medical evaluation asap. You could be dealing with an infectious process (i.e. Std, prostatitis), you could have hemorrhoids (internal and/or external) pulled groin muscle, hernia. Etc. The list goes on. With the limited amount of information in your post and without examing you it's hard to say. If you are still having these symptoms, seek out medical care. Best of luck.