Yeah, that's solid advice. The one thing I'd add from my own playthroughs: don't sleep on Respite if you haven't grabbed it yet. Healing yourself also restores stamina, which sounds minor but it's actually huge on Legendary because you're constantly needing to power attack, sprint away, or bash. It turns healing into a resource management tool instead of just a "stay alive" button.
Also, the previous reply nailed it on the defensive playstyle thing. I notice a lot of people treat Restoration like it's supposed to be a tank build, but it's really more of a "keep yourself functional while you kite and control the fight" skill. Once you internalize that, healing spells feel way less weak because you're not relying on them to outheal incoming damage - you're using them to patch yourself up between positioning moves.
One more thing: if you're burning through magicka that fast, check if you're actually using Restoration or if you're just spamming healing expecting it to work like potions. Potions are instant and free; spells cost magicka and have a cast time. The tradeoff is that spells scale with perks and gear, potions don't. So early on, yeah, potions are objectively better value. But once you have the cost-reduction perks and a halfway decent magicka pool, spells pull ahead because they're essentially free at that point and you're not burning gold.
What's your current magicka at, out of curiosity? If it's under 150 or so, that might be your actual bottleneck rather than Restoration itself being weak.