Is repentance accepted without feeling remorse, and is remorse an essential condition for its acceptance?

Regret is a pillar of repentance, and it is realized by the heart's pain over the sin. This occurs in one who knows the gravity of the sin and its consequences. So, whoever feels sorrow and fears punishment has repented. It appears that the questioner possesses the required regret, but obsessive whisperings prevent her from feeling it. Therefore, she should frequently supplicate, seek refuge (with Allah), and turn away from these whisperings.