Complex sentence: Fréhel then began a relationship with Maurice Chevalier but that too did not last long and after he left her for the much older megastar Mistinguett, the distraught girl, still only 19 years old, attempted suicide.
Split into simpler sentences: Fréhel then began a relationship with Maurice Chevalier but that too did not last long and after he left her for the much older megastar Mistinguett. The distraught girl, still only 19 years old, attempted suicide.