Let \section{} command not pagebreak

Question

EDIT: Fixed by knowing the difference between \include and \input!

I'm writing a paper but can only have 15 pages. A way for me to solve my problem of having too much text is letting the sections in my paper not start on a new page, but immediately following the end of the last section. I write it in article style, and it automatically pagebreaks after a section, as you may know. I've tried many things, such as

\titleformat{\section}{\normalfont\Large\bfseries}{\thesection}{1em}{}
\titlespacing*{\section}{0pt}{\baselineskip}{\baselineskip},

but it didn't work our for me. Any suggestions?

EDIT: It does not pagebreak automatically. Here's my code, I hope it's not too long:

\documentclass[12pt, a4paper]{article}
%\documentclass[a4paper,12pt]{article}
\usepackage[utf8]{inputenc}
\usepackage{url}
\usepackage{hyperref}
\usepackage{graphicx} % Use for Images
\usepackage{here}     % Forced Figure Placement
\usepackage{titlesec} %  for mpdifying \section command so it does not page break
% \titleformat{\section}{\normalfont\Large\bfseries}{\thesection}{1em}{}
% \titlespacing*{\section}{0pt}{\baselineskip}{\baselineskip}
\titleformat{\section}{\normalfont\Large\bfseries}{\thesection}{1em}{}
\titlespacing*{\section}{0pt}{\baselineskip}{\baselineskip}\titleformat{\section}
\usepackage{newpxtext,newpxmath}  % Palatino font
\usepackage{fancyhdr} % Use headers
\usepackage[
    top    = 1.5cm,
    bottom = 1.80cm,
    left   = 2.00cm,
    right  = 2.00cm,
    includeheadfoot]{geometry} % Use similar margins to the Word Template
\setlength{\parindent}{0pt}
% Define the page styles
\fancypagestyle{titlepage}{
    \fancyhf{}
    \fancyhead[C]{\includegraphics[width=\textwidth]{images/banner.png}}
    \renewcommand{\headrulewidth}{0pt}
}
\fancypagestyle{body}{
    \fancyhf{}
    \fancyhead[R]{\thepage}
}
% include bibliography in table of contents
%\usepackage[nottoc,numbib]{tocbibind}
\usepackage[nottoc]{tocbibind}
\renewcommand{\refname}{Bibliography}
% Begin the actual document
\begin{document}
\pagestyle{body}
%\setlength{\headheight}{50pt}
\title{
    \vspace{5cm}
        {\bf
        {\Huge Title}
        }\
        \vspace{9cm}{\LARGE ... & ...}\
        \vspace{2mm}...
}
\date{...}
\maketitle
\thispagestyle{titlepage}
\newpage
\setlength{\headheight}{32pt}
\tableofcontents
\pagestyle{body}
\include{chapters/introduction}
...
\include{chapters/conclusion}
\end{document}