Suggest Treatment For Sore Red Bruise On Foot

I had a red dot and large bruing on my foot that spred to the middle of my 2nd 3rd and 4th toes upward and was very sore. At first I thought it was a spider bite and would go away, however, it has now (after about a week got larger and still a little sore)...is this just a bruise that I can just watch (it has now come up to almost my ankle (I noticed after getting out of the bath)...but here at work doesn't seem to be as dark....any concerns - I noticed someone mentioned Vitamins B12, C, K (I don't take any vitamins) I'm 54. No insurance, so I can't just run to the Doctor - any help would be great