YouTube recently discarded the old \"embed\" code and replaced it with iframe code.
In the new iframe code I found the way to loop+autostart videos on my website, thanks
I came here with a similar question. That question has been solved, heres how i did it. Where you link the source, just get the original embed code, then replace the part that says embed with v. ex:
www.youtube.com/v/lG5aSZBAuPs
(embed was originally here, now its a v)
Now add these attributes (or whatever the name for them would be) to the end of that embed link:
so at the end the link should look like so: