Getting rid of a bad tan line?

I had a rash on my lower stomach and i put a big bandage over it to heal, then I went tanning in a bed one day and took it off, but apparently the adhesive at stayed on me and it sunk into my skin while I was tanning so now I have a sqaure line that is DARKER than the rest of me and I don't know how to get rid of it, because it's not like a normal tanline, where the skin is paler in that place, it's DARKER than the rest of my skin, it's summer now and i look like a freak in a bikini what do I do?! someone please help i'm freaking out ):