The consular officer is correct. You don't need a visa. If you don't stay for longer than three months on any one visit, you don't even need to register. All you have to do is be able to show that your husband is in Italy and that you are going to visit him. If you can do that, the 90/180 rule does not apply to you.
The sources for the above are the free movement directive, 2004/38/EC and the Schengen Borders Code.
"you don't need a visa": Directive, Art. 5(2).
"If you don't stay for longer than three months on any one visit, you don't even need to register": Directive, Art. 6 and Art. 7.
"All you have to do is be able to show that your husband is in Italy and that you are going to visit him": Directive, Art. 3(1).
"If you can do that, the 90/180 rule does not apply to you": Borders Code, Art. 2(5) and 2(6). The former defines non-EU family who fall under the free movement directive as "persons enjoying the right of free movement under Union law." The latter defines "third-country national" to exclude persons enjoying the right of free movement under EU law. When you're traveling with or to join your husband, therefore, you are not a third country national with respect to the Schengen Borders Code, so the 90/180 rule, imposed by Borders Code Art. 6, does not apply to you.
(As an aside, if you're returning in December, that's not within the 180-day period that started in May, so you would not even be in violation of the 90/180 rule if it did apply to you.)
If you were from a visa-required country, you would indeed use the standard Schengen visa application form. It has some notes about certain questions that are not to be answered by people applying under free movement rules.
Some readers will point out that EU free movement rules do not, strictly speaking, apply to your case because they do not affect a country's relationship with its own citizens (and their family members). However, Italian law says that family of Italian citizens must be treated at least as favorably as family of other EU citizens (see What does the spouse of an Italian citizen need in order to stay in the Schengen area for more than 90 days? for a detailed discussion). In other words, this Italian law extends the benefits of the free movement directive to the family of Italian citizens in Italy.