So I had an unfinished mod laying around that added health regeneration via a birthsign.  I'd already tested it and everything was working.  I know there's a fair number of Magicka regen mods, but I wasn't aware of a good Health regen mod, so I created this.

You need at least 50 Endurance to regenerate Health, and at least 50 Willpower to regenerate Magicka.

I used a square root function, so while your regeneration isn't hard capped as long as you continue to increase your Endurance and Willpower, you will quickly get diminishing returns.  At 75 Endurance/Willpower, you will regenerate 0.5 Health/Magicka every 3 seconds (75 - 50 = 25, sqrt(25) = 5, 5 / 10 = 0.5).  At 150 Endurance/Willpower, you will regenerate 1 Health/Magicka every 3 seconds (150 - 50 = 100, sqrt(100) = 10, 10 / 10 = 1).

This mod takes into account the passage of time, and so takes into account resting/waiting and traveling via boat or silt strider.  If you change the timescale, it will also affect the rate of regeneration.

This was made using OpenMW-CS, and thus is an .omwaddon.  There's no reason it shouldn't work for vanilla Morrowind, though, but I can't make any guaranties.  You can either use OpenMW to play Morrowind, or you can try just renaming the file and changing the extension from .omwaddon to .esp.