YOU SAID:

I am feeling better than how I felt yesterday because I was ill yesterday

INTO JAPANESE

昨日病気だったので昨日より気分が良くなりました

BACK INTO ENGLISH

I was ill yesterday so I feel better than yesterday

INTO JAPANESE

昨日は具合が悪かったので昨日より気分がいい

BACK INTO ENGLISH

I felt sick yesterday so I feel better than yesterday

INTO JAPANESE

昨日は気分が悪くなったので昨日より気分が良くなりました

BACK INTO ENGLISH

I felt sick yesterday so I feel better than yesterday