Hello, i have a bump on my lower back right on my spine (above my crack lol sorry) and its very painfull..?

Its to the point where I can't even sit in certain angles, I've had it for as long as I could remember, but just last night it has gotten worse, it feels squishy when I touch it and it has gotten a little more red-er as well. Is this normal? And how serious can it be?