You don't have to feel sorry to be sorry.

Sincere sorrow for sin does not necessarily require having to feel sorry. Just like love, sorrow is an act of the will, not a feeling. And in the same way as one can love God deeply without any emotional reaction, one can also be truly sorry for sin without experiencing anything sentimental. Real sorrow is seen principally in the way one unhesitatingly avoids all occasions of offending God and is ready to do specific acts of penance for any infidelities committed. These are the things to help us atone for the punishment our sins deserve, to overcome bad inclinations, and to strengthen us in doing good.

What are the acts of penance that are pleasing to God? they are: prayer, fasting, almsgiving, small mortifications, putting up patiently with the disappointments and difficulties of life, being ready to accept the monotonous aspects of our job and the tiredness that is part and parcel of work. In particular, we should always be ready and eager to go to Confession well, truly sorry for our faults and sins.

Francis Fernandez, In Conversation with God,

Vol. 4, Ordinary Time: Weeks 13-23