I guess that you will have to sort out your symptoms yourself, and then put them into words that the "experts" can understand. To start with, you need some really expensive test equipment:
With a word-processor, take a short paragraph of text (like the third para of your post) and print it out several times on one page (different size fonts, and a wide margin). You want this in bold type and double spaced. Next - you do not have double vision - you see a second image! When you get this second image, take your sheet of paper, look at the text, and see where the second image is compared to the text on the page. It will probably be slightly more faint than the original (that's why the bold type). It could be above or below (that's why the double spacing), and displaced to the side as well (that's why the wide margin). Now you can tell the experts where the second image is.
The next question is the time of day that it happens. Morning, mid-day, evening, all the time, only when you get tired? It sounds like it is as you start to get tired and then see the second image - that could come with the MS. If you get it most of the time, and it gets worse when you are tired, that is something that the optician should be able to sort out. Sometimes the images that the lenses in your eyes are not perfectly aligned, and spectacles with a slight degree of prism in their prescription can sort this out.
But, the really big but, is that you are not seeing double - that's in your head!
You are seeing a second image - and you can now say where in relation to the main one - and that is an optical problem.
Start testing yourself now, so you know what to say.