Why does all knowledge disappear in kama bhava?

Whenever kama bhava rises in my body, all the knowledge of witnessing it in sakshi bhaav, disappears and i tend to give in to the bhaav. I really want to understand how to keep it away from me

Slowly and gradually, i am getting stronger and focused, but that tide is too strong. Help me understand why knowledge disappears in such circumstances.

When the bhaava goes away, then i remember everything. But by then it's too late.

Please help.