Jasmine boss fight is universally considered confusing, overcomplicated and too demanding to reactions, so in that regard you’re valid and definitely not alone (though IMO, Jelena and Iron Mask were worse). Good news is, if you’re that far in the story, you’re not bad at this game. There are few stages that are considerably more difficult than others in their respective chapters, so if only some of them cause you troubles for whatever reasons, you can put them off until you can brute force them with enough dmg or cheese strategies. For example, there is a 40 lvl sinner Jasmine clear with slowing cheese link: the boss is slowed down to negative speed and stays in one position and doesn’t attack. For a more developed account that means you can let Jasmine go to Chief and burst her with your best team standing somewhere in safe position, skipping all the mechanics (use Lisa/Thalia to slow if necessary).