他未爱我入骨我待他如命
[tā wèi ài wŏ rù gú wŏ dài tā rú mìng]
The phrase 'He did not love me profoundly but I treat him like my life' indicates unrequited love where one holds deep feelings despite not being equally loved back. It signifies intense dedication to someone even when such sentiment is not reciprocated.