My LaTeX makes me pagebreaks after each subsection because my subsections are in separate files. I use the command \\include{file} which adds a pagebreak after
You can stop pagebreaks caused by \include by placing \let\clearpage\relax before it. So,
\let\clearpage\relax
\include{file1}
\include{file2}
\include{file3}
would put the contents of the three files (and any subsequently included files) together without a pagebreak between them. If you want to stop relaxing the \clearpage command, then wrap the files to include without pagebreaks within a group like this:
\begingroup
\let\clearpage\relax
\include{file1}
\include{file2}
\endgroup
\include{file3}
This will stop a pagebreak between file1 and file2, but insert the normal pagebreak after file2. (Note: I do not know if this interferes with referencing and page numbering, though I imagine it should be OK.)