I have played around a bit with remote uploads to video hosting services and it was a terrible experience. I was trying to replicate a video from one hosting provider to another but it never worked despite the fact that they are claiming to support that specific host. The only way that I managed to make it work was with direct file link from my seedbox.
From what I understand you are trying to migrate from doodstream to your own host which is the opposite of what I was trying to do. However a remote upload is nothing special it's just a normal download executed by a remote server. I believe that doodstream were providing download link to your videos, you will need some kind of automation that will get the direct download link for each file. Then you will need another service on your server that get these links and download the files. If my memory does not lie the download links from doodstream are not direct links, they send you to a page where you have download button that will direct you to the cdn host and this should be the direct download link.
I'm not sure if the steps that I gave you are 100% correct but it should looks something like this.
