Anxiety is love's greatest killer. It makes others feel as you might when a drowning man holds on to you. You want to save him, but you know he will strangle you with his panic.

This quote is saying that feeling anxious can be very overwhelming. It can be like trying to help someone who is drowning. You want to help them, but sometimes their fear and panic can be so intense that it can be suffocating and dangerous to you. Anxiety can prevent people from being able to fully love and accept others.