Anaconda installation modifying .bash_profile on Mac OS X [migrated]

I installed Anaconda on my Mac (Mojave) and now whenever I start a shell it automatically activates the conda environment. This was totally fine until I realized some of the commands in my .bashrc were not being executed on startup. In particular, I had increased HISTSIZE and HISTFILESIZE but they always seemed to be stuck at their default values of 500. After some googling, I learnt that because of my anaconda installation, it was my .bash_profile that was being used on startup and not .bashrc. This is what my .bash_profile looks like (see below), just adding commands from my .bashrc file (e.g., HISTFILESIZE=100000) to the top of my .bash_profile appears to do nothing. Any suggestions on what I am doing wrong? Thanks!

# Setting PATH for Python 3.7
# The original version is saved in .bash_profile.pysave
PATH="/Library/Frameworks/Python.framework/Versions/3.7/bin:${PATH}"
export PATH
# added by Anaconda3 2019.07 installer
# >>> conda init >>>
# !! Contents within this block are managed by 'conda init' !!
__conda_setup="$(CONDA_REPORT_ERRORS=false '/anaconda3/bin/conda' shell.bash hook 2> /dev/null)"
if [ $? -eq 0 ]; then
    \eval "$__conda_setup"
else
    if [ -f "/anaconda3/etc/profile.d/conda.sh" ]; then
# . "/anaconda3/etc/profile.d/conda.sh"  # commented out by conda initialize
        CONDA_CHANGEPS1=false conda activate base
    else
        \export PATH="/anaconda3/bin:$PATH"
    fi
fi
unset __conda_setup
# <<< conda init <<<

# >>> conda initialize >>>
# !! Contents within this block are managed by 'conda init' !!
__conda_setup="$('//anaconda3/bin/conda' 'shell.bash' 'hook' 2> /dev/null)"
if [ $? -eq 0 ]; then
    eval "$__conda_setup"
else
    if [ -f "//anaconda3/etc/profile.d/conda.sh" ]; then
        . "//anaconda3/etc/profile.d/conda.sh"
    else
        export PATH="//anaconda3/bin:$PATH"
    fi
fi
unset __conda_setup
# <<< conda initialize <<<