Capricorns are the most disciplined and uniform in nature. They are aware of practicing self-control even when they don’t intend to. So, it is a hailstorm for them when someone breaks their trust, it gets hard wrapping their mind around that situation. They’ll throw themselves into work, take up new projects and do everything in their capability to do what they always wanted.
However, the truth is they are hurting bad deep inside and they try to hide it better than the rest. They would kill their time, often wondering how things faltered to the point of betrayal. But if you mean it when you are confessing, a Capricorn can recognise. They might then give a chance or two to rebuild the relationship if they think it is worth it.