Just replaced my brake pads, now it sucks.

Bking

The service guy at Nissan told me I needed to replace the front brake pads. After the change I almost got into an accident because it took a long time for the brakes to stop my car. I thought maybe it's new and needs time to "break-in". After a full day of driving the response from the brakes seemed to have improved but it was not like before. Before the change I needed only to step on the brakes relatively lightly to stop my car, but now I need to step fairly hard to do so.

I called my service guy and he told me these "brembo" brakes takes some time to break-in and told me to go on a highway and hard brake a few times.

I feel like the brakes were not the problem but just the "sensitivity" of the brake pedal with the brakes themselves. Can the brakes be adjusted/calibrated?

Thanks in advance.