“…a burnt-offering, a fire-offering, a satisfying aroma to Hashem.” (Lev.1:9)
R’ Yaakov Tzvi Mecklenberg explained that a person shouldn’t think that s/he achieves forgiveness with their sacrificial offering. Rather, it is to be an aroma, a scent of the changed life that will now commence. You encounter the smell of something before you encounter the thing itself. So too, the sacrifice must presage personal transformation in the sinner.
Does HaShem ever get’s tired of us sinning and repenting over and over again?
No. Hashem is described in the Torah as infinitely patient with us.