i feel the same way. im far into the stories but my character is only level 19. either i am doing something wrong or other people *ahem* cheating.
the most efficient way to level in every elder scrolls game is to use skills. whether they are ones you care to level or not, using them only helps you level faster. so use those illusion and alteration spells even if you don't care for them - as they are easy to level with. but all skills do it, so block, etc.
also, you level up soooo much faster if you don't follow the storyline. you can beat both main stories before level 20 - i'm level 48 now and haven't finished either. exploring on your own, and using your skills are what level you up. don't go for the quickest kill - go for the one that uses the skills you want to level.
so explore dungeons and take out bandit/forsworn camps. use your skills as much as you can, even when you don't need it to beat the enemy. do the little side missions as they rack up fast.every kill, every skill level, every lock pr pocket picked, etc levels you up.
it seems obvious, but i don't think it is. when i follow through the main stories, i barely level - but when i do side missions and clear camps on my own, the points come faster than you'd think.
ok, and one more cool thing i found,
if you happen to mine - if you stop the process after the first ore/gem is added but before the second, and then start again, you will always get something in 3 hits. since each vein has 9 hits, if you stop after every third
you can get 3 ores/gems every time you mine, rather than 10% of the time.
I'm only lvl 19 but Destruction is lvl 44. I spread my perks over Restor, Destruction, and Conjour, have a couple in Arch, Speech, and even one in 1-hand combat.
I dont know how people have 100 lvl anything and Legendary Dragon armor they smithed themselves.
because they don't spread out, they focus on one thing and level it to max. sneak is the exception imo, as if you stay sneaking it levels up all the time almost, without focusing on it. i'll be 100 in sneak in the next hour, but have done nothing other than use the skill to do that. i've played 85 hours, i'll check my actual game time when i load it up next. probably close to 60.
tl;dr - if you focus on one skill you max that skill quickly, if you go to the other extreme and level every skill whether you like it or not, your character levels faster. oh. and mine properly, you get more!