Far from irritating my skin, it's actually more stable than before I started using it.
Literal
Skin [subject-が] stinging far-from, using before [more-より] skin [subject-が] stabilizing [explanatory-んです].
ヒリつく ('to sting, to tingle with irritation') is a skin-care mimetic. どころか ('far from, let alone') is the key grammar — it dismisses the negative expectation and pivots to a positive reality. 安定してる ('is stable') is a skincare term for skin not reacting. んです adds the explanatory nuance of sharing a personal discovery. A beauty review sentence.