The Verdict: Not eligible
Ordinary naturalisation is closed to you, because it requires giving up your current citizenship. Look at the Croatian routes that let you keep it: Citizenship by Descent, Diaspora & Religious Return, Marriage and Exceptional Talent.
Article 8(1)(2) of the Croatian Citizenship Act requires release from your existing citizenship, or proof that release will follow once Croatia admits you. On the ordinary route it cannot be waived.
Four routes are exempt from it:
Article 11, for emigrants who left before 8 October 1991 and their descendants, with no residence and no generational limit.
Article 16, for members of the Croatian people living outside Croatia, wherever the family came from.
Article 10, for the spouse of a Croatian citizen who holds permanent residence and lives in Croatia.
Article 12, for a person whose admission is in the interest of the Republic, with a ministry behind the case.
If your own state does not allow release at all, that is different from being unwilling: article 8(3) lets a declaration take its place. Take this quiz again and choose the first answer.