Restoration's not a trap, but you're hitting the wall that catches a lot of people early on - the scaling is front-loaded toward late game, and you're feeling the cost before the payoff.
Here's the actual issue: healing spells cost a ton of magicka relative to their output until you get the perks that multiply their effectiveness. At level 22, you probably don't have the perk that boosts healing spell power yet (the one that makes them heal for more), and even if you do, one rank isn't enough. You need like 2-3 ranks in that perk tree before healing becomes efficient compared to just chugging potions. Plus your magicka pool is probably still small, so you're running dry fast.
The efficient path early on honestly is hybrid - keep a stack of cheap healing potions as backup, but level Restoration anyway because the perks will pay off. Don't dump points into magicka regen gear yet; that's more of a mid-to-late thing. Instead, grab the perks that reduce spell costs (there's one that cuts Restoration spell costs specifically) and the one that makes healing spells work better. Once you have those, the math flips and spells become way more efficient than potions.
On Legendary you might also just need to play smarter defensively - abuse cover, kite enemies, use wards or buffs instead of pure healing. Restoration isn't really built to keep you standing in a fireball; it's more for topping off between fights.
What perks do you have so far in Restoration? That'll help me tell you if you're missing something obvious or just need to grind a few more levels.
