I have no other choice.....*drops to knees* PLZ SOMEBODY HELP MEEEEEEE!!!!

Ok so i was using the super old version of gimp like 2.6.4 somethin idk but yea so i downloaded the newest versiom 2.8! and I CAN NOT BLEND!!!!

I'm trying to blend somepictures together with the eraser tool but when i erase it just erases the color leaving it white instead of showing the layers underneath which im used to happening!

SOMEONE WITH GIMP PLZ HELP ME TTWTT ive tried i think almost everything so far adjusting the opacities and sizes and everything that seemed to work DOESNT WORK! Im sorry for my ranting but im on the verge of breaking *cries off in corner*