Morrowind is a great game. However, it would be even better if it was less buggy. I recall having some loading issue back in the day when I was playing it. I made multiple saves when I think I have played long enough w/o saving or do something that feel was significant enough to save the game. I would archive all my saved games by compressing them using WinRar, 7-Zip or whatever file compression program you like using.
Sometimes to get around the issue you are having is to load up and play an older save. This same thing happens in Oblivion and Fallout 3. Not sure about Skyrim since I have not played it yet.
If you are playing with mods that affects gameplay, then try disabling mods one at a time and load the game. If it loads successfully then save as a new saved game file. Then exist out of the game and disable another mod, load and save again. Do this until all mods have been disabled and save your game as a "Clean Copy" that way you know it only relies on the base game.
If you have any weapons, armor or anything that is unique to any of the mods you are using, then put them in a crate or other container before disabling the mod. Otherwise, that item will disappear from your personal inventory (which is natural), but whatever the weight of that / those items are will still be counted in the current total weight of all the items you are carrying. Even if you drop everything, you will still be "carrying" those items that no longer exist.