[Tex/LaTex] Vertical subfigures with captions on left

Question

This is what I want

I've tried a million things from floatrow package, subfloat, sidecap, etc. but nothing seems to work. This shouldn't be that hard to achieve I feel like but I'm all out of ideas.

Please help

edit: Current working example

\usepackage{floatrow}


\begin{figure}[htp]
%\centerline{
  %\ffigbox{%
    \begin{subfloatrow}
      \fcapside[15mm]
      {\includegraphics[scale=.4]{zeta_zeropoint_05_A}}%
      {\caption{blah\\}}
   \end{subfloatrow}
  \begin{subfloatrow}
      \fcapside[15mm]
      {\includegraphics[scale=.4]{zeta_zeropoint_05_B}}%
      {\caption{blah}}%
    \end{subfloatrow}
    \begin{subfloatrow}
      \fcapside[15mm]
      {\includegraphics[scale=.4]{zeta_zeropoint_05_C}}%
      {\caption{blah\\}}%
    \end{subfloatrow}
    %}
  {\caption{Fitting for subsample 1}}
  %}
\end{figure}

Answer 1

Do you mean something like this:

\documentclass[a4paper]{article}
\usepackage{caption,floatrow,graphicx}
\usepackage[showframe]{geometry}

\DeclareCaptionSubType[alph]{figure}
\captionsetup[figure]{labelsep=colon}
\captionsetup[subfigure]{%
  font=footnotesize,labelformat=brace,labelsep=space,labelfont=bf}
\floatsetup[subfigure]{capbesideposition={left,top},capbesidewidth=4cm}

\begin{document}

\begin{figure}[htp]
  \ffigbox{%
    \begin{subfloatrow}
      \fcapside[\FBwidth]
        {\caption{Subcaption a)}}%
        {\includegraphics[width=5.5cm]{example-image}}%
   \end{subfloatrow}

   \begin{subfloatrow}
      \fcapside[\FBwidth]
        {\caption{Subcaption b)}}%
        {\includegraphics[width=5.5cm]{example-image}}%
    \end{subfloatrow}

    \begin{subfloatrow}
      \fcapside[\FBwidth]
        {\caption{Subcaption c)}}%
        {\includegraphics[width=5.5cm]{example-image}}%
    \end{subfloatrow}}
  {\caption{Fitting for subsample 1}}
\end{figure}
\end{document}