Linking the old messenger account with the new one on FB

I have Messenger without Facebook and it curently doesn't work (I'm not able to log in it and have no possibility to contact support centre, because I don't have Facebook). Because of this I have decided to set up an Facebook account. Nevertheless I don't want to lose my contacts and messeges on Messenger. Is there some possibility to link the old Messenger account with the one on Facebook, when I have the same phone number?

Thank you very much.