My mole always looked normal, and suddenly now is tender with two blood-filled bubbles on it and redness all around. (photo)

Any new changes in pigmented moles warrant prompt evaulation by a specialist. It can be one of the signs of malignant change so you do not want to ignore it.

It is very difficult to tell from your photo what exactly is going on with your mole. To be safe, you should be carefully evaluated by a
board certified dermatologist. Please use the ABCDE's as your guide for
when to be concerned about moles: A for Asymmetry; B for
Irregular Borders; C for
Black or uneven Colors; D for diameter greater than a pencil eraser; and E
for a growth that is Evolving or changing. If necessary, it is an
extremely simple five minute procedure for a dermatologist to remove the mole
using either a "punch" or a "shave" biopsy which typically
leaves a minimal scar. The mole can then be checked microscopically for
reassurance.