How do I display a very wide table at the bottom of a page over two columns?

Question

I'm writing a paper in LaTeX according to a CogSci template which uses two columns. However, I have a very wide table which needs to span accross both columns to be shown correctly. I want this table at the bottom of the current page and therefore could not use table* (which can only place things at the top of the current page or at that position). So I found online that I needed to use a local minipage, which kind of works fine as you can see below. The table is at the correct spot and apans two columns; however the column in the right side is superimposed on the table rendering both unreadable.

How can I solve this?

I use this code for the table:

\begin{table}[b!]
\begin{minipage}{\textwidth}
    \centering
    \setcounter{table}{3}
    \begin{tabular}{l|l|l|l|l|l|l|l}
    ~                        & $P$    & $S$     & $SP$   & $T$    & $TP$      & $TS$      & $TSP$       \\ \hline
    \textit{no restrictions} & $.150$ & $.013$  & $.106$ & $.036$ & $< .001^*$ & $< .001^*$ & $< .001^*$  \\ \hline
    $P$                      & -      & $.022$ & $.557$ & $.640$ & $.006$   & $.004$  & $ .001^*$ \\ \hline
    $S$                      & -      & -       & $.020$ & $.002$ & $< .001^*$ & $< .001^*$ & $< .001^*$  \\ \hline
    $SP$                     & -      & -       & -      & $.888$ & $.032$    & $.003$    & $< .001^*$  \\ \hline
    $T$                      & -      & -       & -      & -      & $.008$    & $< .002$ & $< .001^*$  \\ \hline
    $TP$                     & -      & -       & -      & -      & -         & $.403$    & $.022$     \\ \hline
    $TS$                     & -      & -       & -      & -      & -         & -         & $.006$     \\ \hline
    \end{tabular}
        \caption{Overview of $p$-values for every combination of the restrictions\label{table:posthoc}.}
            \end{minipage}
\end{table}