We're worried about your braking. Having to brake suddenly all the time means you're not doing enough observation so you’re reacting to danger late. This video will go into why you might be doing this and how you can work on your skills.
A few braking tips
At 50mph it takes around 13 car lengths to stop. If you're going faster than that, you’re going to need to give yourself even more space.
You need to read the road better. Always be scanning for danger - including on pavements and driveways.
If you're braking late or sharply, it could be because you're getting distracted. You only have to look away for a second to miss something important.