Complex sentence: With her addiction worsening, Phillips checked into a rehab facility; while undergoing treatment, she cut some sides for Roulette in 1969 and upon her release, she moved to back to Los Angeles and re-signed with the Atlantic label.
Split into simpler sentences: With her addiction worsening, Phillips checked into a rehab facility. On her release she moved to back to Los Angeles and re-signed with the Atlantic label.