How did Gerry Rafferty (RIP) manage to battle alcoholism, depression, and the music industry, yet produce such wonderful music?

Sometimes.. From The Greatest Pain And Sadness  Comes Beauty. Edgar Allen Poe Was Very Depressed His Whole Life.. Vincent Van Gogh Was Very Depressed A Long Time. I Write The Best Poetry That Gets Published.. When I Am Heartbroken  Or    Angry Or  Disappointed

Was he battling those things while making music?
If so I am perplexed on how he did it..... But perhaps he was a master of disassociation and separated his personal issues from his professional passions.
Otherwise, it seems it's just par for the coarse in music, battling demons so to speak.

Maybe becouse of what he battled within himself gave him a great insight and understanding that along with his musical talent made for great music,