Dude, you have an anal fissure.
A small rip on your sphicter muscle.
These pop up every now and the if you are a straining with a bowel movement that is larger than normal, usually. With a dildo that's a bit thicker, that could cause one too.
They itch, they bleed but they are curable. The blood on the toilet paper is bright red because it's a rip in the skin. It looks like a lot of blood, especially if it drips into the toilet bowl.
Add more fiber to your diet, drink more water, lay off the overly, girthy dildos for a bit.
You don,t have cancer. Go see a protologist. They treat this all the time. Also, you don't need surgery. It's a cut and only a cut on your sphincter.
Sklar