YOU SAID:

If you do not procrastinate, you would have done your work since yesterday.

INTO JAPANESE

先延ばしにしなければ、昨日から仕事を終えているはずです。

BACK INTO ENGLISH

If I hadn't procrastinated, I would have finished my work since yesterday.

INTO JAPANESE

もし先延ばしにしていなかったら、昨日から仕事を終えていただろう。

BACK INTO ENGLISH

If I hadn't procrastinated, I would have finished my work since yesterday.