If you will use only potions and medicines that you'll find, it shouldn't increase your tech or magicka percentage. Am I right?
If not, your character may be so ugly, evil and stupid, and won't be able to understand idea of healing :)

You can always buy healing potions/healing salves. They aren't that expensive and you will be (no matter what kind of character you play) be rolling in money during the game anyway.

If you're thinking about role play reasons for not being able to heal your character, I think you can go two routes. As Lukier said, you could go the path of: the character is too dumb to understand that he needs to heal himself regularly, and so the character can be a berserker type who only heals by resting. Or you can go with a dumb character who isn't quite dumb enough to not know that he needs to buy things to heal himself at some points.

Thanks

When I think about it is the same situation as in real life.
I dont know how to make medicine, but I know that I can buy it in a shop.

Your hero could luckily find lifesteal dagger and heal himself accidentally by magic weapon ;-)