'according to myself is wrong, simply because 'according to' means ' on the authority of', and one would never quote themselves as the authority, it's just weird. That's also the reason why 'according to' is followd by the source of the opinion as it is the source that carries the authority not the opinion on its own.
can't trust the Internet all the time. can you imagine there are 3,700 listings of "according to my opinion" on the Internet?
similarly, by my opinion, as in "this book, by my opinion, is garbage," is wrong and should be replaced by "in my opinion," but this is on the Internet.
BMO, for the sake of being working in Germany in the past I picked up the form "To my opinion" that I found out later on is not correct either! Sometimes it's a bit dangerous for non-native speakers to rely on other non-native speakers idioms or expressions in the belief they are correct...