YOU SAID:

my drawing skills are very crappy if I don't say so myself

INTO JAPANESE

自分のことを言っていないと、私の描く技はとても駄目です。

BACK INTO ENGLISH

If I do not tell myself, my skill is very useless.

INTO JAPANESE

私が自分に言わなければ、私の技能は非常に役に立たない。

BACK INTO ENGLISH

If I do not tell myself, my skills are not very useful.

INTO JAPANESE

私が自分に言わなければ、自分のスキルはそれほど有用ではありません。

BACK INTO ENGLISH

Unless I tell myself, my skills are not that useful.

INTO JAPANESE

自分に言わない限り、自分のスキルはそれほど有用ではありません。

BACK INTO ENGLISH

Unless I tell myself, my skills are not that useful.