章、节、小节标题的字体更改

Question

所以，我正在努力更改乳胶中标题/部分/小节的字体。

这是我的代码：

% !TEX TS?program = pdflatexmk

\documentclass[fontsize=12pt]{book}

\usepackage[T1]{fontenc}

\usepackage{amsmath}

\usepackage{mathpazo}

%changing font of section/chapter title
\usepackage{fontspec}
\usepackage{titlesec}
\newfontfamily\headingfont{Papyrus}
\titleformat{\chapter}{\LARGE\headingfont}
\titleformat{\section}{\LARGE\headingfont}
\titleformat{\subsection}{\Large\headingfont}
\titleformat{\subsubsection}{\large\headingfont}



\title{my report}
\author{user name}
\date


\linespread{1.5}

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
\begin{document}
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
\maketitle
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
\tableofcontents
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
\chapter{introduction}
text : intro
\section{first section}
text :  section
\subsection{this subsection}
text :section
\subsubsection{this and that subsection}
text :subsub
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
\end{document}

这是输出： 该字体仅在chapter和中实现subsection。不适合其他人。而且编号也丢失了。例如，没有titlesec，fontspec这就是它的样子。章节和小节的编号随之丢失。我找不到错误。（使用 fontspec 也有点烦人，因为它找不到默认的乳胶字体，因此必须将文件复制粘贴otf到工作目录中）