、。
Because I decided I'd follow you anywhere you go.
Literal
You [genitive-の] go place [conditional-なら], anywhere [target-へでも] follow-go [quotative-と] decided [explanatory-のだ-emphatic-もの].
An emotionally-charged explanation. The ending のだもの (often shortened to んだもの or just もん) is the feminine/childish 'because, after all' — it's the explanatory のだ followed by もの ('you see, after all'). Very soft, emotional, often carrying a pouty or pleading tone. 付いてゆく ('to follow along') uses the literary/slightly formal ゆく instead of more casual 行く — same verb, different register. どこへでも ('to anywhere') combines destination へ with でも ('even/any').