I had that pain both pre and post op...I have it every once in a while out of the blue when I am walking now. But, no bruise. Before my surgery though, the bunion would just absolutely throb and ache no matter which direction I was laying. Now, I don't have any pain in the bunion, but pain in other places.......go figure!
Anyway, have you tried icing it?? Also, taking a hot bath and massaging it and then icing it seem to help me. But, really until you have the surgery, there won't be much you can do to reduce the pain....I know how you feel. That's why I chose to get the surgery.
There is one other option you can ask your doctor about. Prior to my surgery, about three years prior, I started getting cortisone shots in the joint. I got them once a year until the last year when I got two (6 months apart) and then they no longer worked. Cortisone shots can eat at the joint if you get too many, but maybe one just to get you to the surgery might be helpful? For me it relieved the pain quite a bit so that I could continue to be on my feet until I decided on surgery. It was only when the injections no longer had any benefit that I did the surgery. So, you might want to inquire about it. Some people don't like to get them, I only had positive benefits with them....so you have to decide. And my joints were not effected at all. Since my surgery I received one injection into the scar, under the skin, to help reduce the inflammation in the scar itself.