[Tex/LaTex] Adding a line break after \paragraph section and making it justified

Question

I had a friend help me change the \paragraph section to include a line break after the end of the section title. However the end result is a ragged section that isn't justified and if the title is too long and requires more than one line it ends up away from the margin.

Is there a better way to achieve a justified \paragraph (or \subparagraph) with a line break, and on another note a way to control the line spacing between the \paragraph and the text?

MWE:

\documentclass{scrreprt}
\usepackage[T1]{fontenc}
\usepackage{lipsum}
\usepackage{setspace}
\usepackage{kpfonts}
\usepackage[T1]{fontenc}
\usepackage[left=2.5cm,right=2.5cm,top=3cm,bottom=3cm]{geometry}

\doublespacing

\setcounter{secnumdepth}{5} %

\makeatletter
      \renewcommand\paragraph{\@startsection{paragraph}{4}{\z@}%
      {-3.25ex \@plus -1ex \@minus -0.2ex}%
      {0.01pt}%
      {\raggedsection\normalfont\sectfont\nobreak\size@paragraph}%
      }
\makeatother

\begin{document}

\chapter{Testing begins}

\section{Going deeper}

\paragraph{Testing an unnecessarily long title to see what happens with the end of the paragraph margin, whether it aligns to the text margin or not}

\lipsum[1]

\end{document}

Answer 1

Simply remove \raggedsection from your definition.

MWE

\documentclass{scrreprt}
\usepackage[T1]{fontenc}
\usepackage{lipsum}
\usepackage{setspace}
\usepackage{kpfonts}
\usepackage[T1]{fontenc}
\usepackage[left=2.5cm,right=2.5cm,top=3cm,bottom=3cm]{geometry}

\doublespacing

\setcounter{secnumdepth}{5} %

\makeatletter
      \renewcommand\paragraph{\@startsection{paragraph}{4}{\z@}%
      {-3.25ex \@plus -1ex \@minus -0.2ex}%
      {0.01pt}%
      {\normalfont\sectfont\nobreak\size@paragraph}%
      }
\makeatother

\begin{document}

\chapter{Testing begins}

\section{Going deeper}

\paragraph{Testing an unnecessarily long title to see what happens with the end of the paragraph margin, whether it aligns to the text margin or not}

\lipsum[1]

\end{document}