I'm level 55 and 160 hours into my character. He is a heavy armor Mage with 100 in destro, resto, smithing, heavy armor and enchanting. I'm getting bored of him because he is too overpowered (nothing is remotely hard on master difficulty). I want to try a stealth archer with no enchanting or smithing (use armor found), the only thing is I also have the urge to finish exploring everything and questing on my main guy... Oh what to do?

Start a new guy and do everything you haven't done with your main guy first.

Or

Start a new guy and do everything you have already done so you can continue your main guy and still be amazed.

Or

Start a new guy and do whatever you want.

Restart and avoid Smithing/Alchemy/Enchanting not to mention using ever friendly NPC's for grinding/training. Enjoy the flow but stay away from the overpowering abilities. Nothing is wrong by upgrading your armour/weapon to "Fine" though.

Cut your hands off and play with your tongue for even more of a challenge.

Try different builds.

Finish everything with your main guy.

The best things about these games is you can be whatever you wish with the options given.