This is really scaring the crap out of me... I have this lump on my head?

but its not a zit or anything. Ive had it for about a year and a half and it never bothered me before, but now its grown more than twice the size (almost the size of a dime). It used to be firm and without any pain but now its a little squishy... it might be sebaceous cysts, Basal cell carcinoma, or Nonmelanoma skin cancer. But ive looked up all these and none really look exactly like mine, all though reading up on them they all have similar characteristics. Mine has no color, just the color of my normal scalp that looks really swollen like there was a round marshmallow under it. (I know sounds so gross) I know i should see a doctor, but i just started a new job and health insurance doesnt start til november... does anyone know what this might be? and maybe some remedies that can help? Thanks so much!!!