Explanation for those redirection loops
https://support.cloudflare.com/hc/en...redirect-loop-
So in shortness it looks like this (I assume):
a) if you have your own certificate (lets encrypt etc) -> then switch the SSL option to Full (
https://support.cloudflare.com/hc/en...-options-mean- ) and use htaccess redirect
b) if you don't have an SSL certificate then forget about htaccess redirection and use the 'Always use HTTPS' at CF.