Well if you spend all your time on alchemy, of course you're going to be the weak kid in class, you bloody fool!
I know, levelling was broken/badly implemented in Oblivion, but I think that the system is a proper RPG system - it gives you the tools to be what you want to be. You could have become the best Alchemist in Cyrodill. Ok, you wouldn't really be able to do anything else, but that's your fault for not striking the right work/life balance. In theory you should be able to keep quaffing the magnificent health potions you've created while dealing 2dmg with each strike.
I'm liking Skyrim a lot. I was fully prepared to dislike it, and it really is 'just' Oblivion again, but nonetheless I'm completely charmed by it. It's the world building and the incidental details and quests that do it for me.