YOU SAID:

I am so full from eating so much

INTO JAPANESE

私はそんなに食べてからいっぱいです

BACK INTO ENGLISH

I have been eating so much since

INTO JAPANESE

私はそれ以来ずっと食べてきました

BACK INTO ENGLISH

I've eaten since then.

INTO JAPANESE

それ以来、私は食べました。

BACK INTO ENGLISH

Ever since, I ate.

INTO JAPANESE

それ以来、私は食べました。

BACK INTO ENGLISH

Ever since, I ate.