Will my hand be okay if I had a boxers fracture and I didn't get it treated?

Maybe. Many boxer's fractures (fractures of the small finger metacarpal neck) can be treated non-surgically. However, a period of immobilization in a splint or cast is usually necessary to allow for appropriate bone healing. For best results, consider operative intervention or immobilization. Once the fracture begins to heal, therapy exercises can be helpful to maximize hand use and strength.
YES. Only in extreme rare cases will a boxer's fracture really be so bad that a person will have a problem with it. But -- be sure to have hand surgeon look at the x-ray to confirm that it really is that. Typically -- and very honestly -- folks do best with the least amount of treatment.