The Speechcraft minigame in Oblivion is genuinely a design choice that didn't age well, ngl. You're not doing anything wrong - it's just a different philosophy than Skyrim's approach, and yeah, it can feel like a slog if you're not built for it.
The real answer is that you don't have to win every persuasion check. Failing one or two isn't the end of the world - you can usually just come back later when you've leveled up Speechcraft more, or find a different dialogue path entirely. A lot of NPCs have multiple ways to get what you want out of them, and some quests have workarounds if you fail the charm route.
That said, if you want to make it less painful: pump your Personality stat (the attribute, not the skill) because it directly affects your success rate in the minigame. Breton is actually solid for this since you can stack perks - there's one early in the Speechcraft tree that boosts your persuasion chances, and another that makes the minigame itself easier (I think it increases the angle you can click? been a while). Get those and suddenly it stops feeling impossible.
Also, the minigame gets way more forgiving once you understand it's not about perfect clicks - you're fishing for a range, not hitting a bullseye. Once you get the rhythm down it becomes almost automatic, even if it's still clunkier than Skyrim's system.
If it's still driving you up the wall, there are mods that simplify or replace the minigame entirely, but honestly give yourself another 5 hours and you'll probably stop minding it as much.
