I think this quote from Pascal, that “we desire to live an imaginary life in the mind of others” may explain this quote from Baudelaire that “when I have inspired universal disgust and horror, I will have conquered solitude.”
“Conquering solitude” I’m equating with “living a real life in one’s own mind.”
Baudelaire is imagining a situation in which he has become so disgusting to others he can no longer pretend they might admire or respect him, and is consequently free of them and the imaginary life they inspire.