Always make a backup before editing any .conf or.ini files in XAMPP by simply 'drag and drop' and at the same time holding down the Ctrl key to make a 'Copy of' the file - you always then have a point to return to that you know worked before you made your changes.
You can add your single IP to the New XAMPP security concept section in the httpd-xampp.conf file that should allow access to the list of folders also in that section.
Allow from ::1 127.0.0.0/8 xxx.xxx.xxx.xxx \
Keep a single space between entries using the other entries as an example. Save the file and restart Apache.Do not post this IP on any open forum
and try and keep it known to only those you trust or you may open a big security hole.
Alternatively you can add another section below the default for the phpmyadmin folder only thereby keeping the defaults in place, like so
Deny from all
Allow from ::1 127.0.0.0/8 xxx.xxx.xxx.xxx\
fc00::/7 10.0.0.0/8 172.16.0.0/12 192.168.0.0/16 \
ErrorDocument 403 /error/HTTP_XAMPP_FORBIDDEN.html.var
This is in addition to the unchanged default section and goes in as the next entry in the conf file below the default section with a single space between them.
When you get access to phpMyAdmin select your database and change the host setting to % (any host).
Restart MySQL to be sure that your changes have been read.
Recommended - if you are paranoid then delete your edits in the httpd-xampp.conf file and return the section to the defaults, knowing now how to create an access for your IP when ever you need it, save the file and restart Apache.
I have no way of testing this for you, so feed back on this solution will be most helpful.