I'm really getting worried about this mole on the side of my head. Is this something that should be taken care of immediately?

From your picture, the mole appears to be benign. But to be safe and fully reassured, 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 your mole by doing a "shave" biopsy which typically leaves a minimal scar. The mole can then be checked microscopically for reassurance.

If your mole is changing at all, then it's best to see someone soon. Always use the ABCDEs to evaluate sites. A - asymmetry, B - border, C - color, D - diameter, E - evolving/elevation. However, what I always tell people is that you know your body, and if you are concerned, see someone. It will always be better to hear that it's nothing, than to hear that you should have come earlier.... right? "This answer has been solicited without seeing this patient and cannot
be held as true medical advice, but only opinion. Seek in-person
treatment with a trained medical professional for appropriate care."