Take Your Time
You don't need to have surgery ASAP—if there is a lump in your breast, chances are, it's been growing there for three to five years. Waiting a couple of weeks is not going to make a difference when it comes to breast cancer.
By the same token, try not to overwhelm yourself with too much information and conflicting advice (especially from well-meaning friends and relatives). At a certain point, you have to stop the information gathering process and trust your gut.
Find the person on your medical team who you think understands you best. Lay out your treatment options and ask him to evaluate them, making sure to discuss why he thinks you should go with a particular plan. At a certain point, you have to tell yourself that you have all of the information that you need, and that it's time to make a decision.