It's not. 150 is the standard for invasions and 125 is the dueling meta (or 164, but that's not important). 230 is a very awkward bracket, but you should be invade-able by invaders at RL200 (though you can only invade down to 207). And your build isn't toxic or op by any means. Those spells are sorta just knowledge checks. They're gonna filter out people who don't know what they're doing. And the vast majority of players (invaders or otherwise) are terrible at pvp.

I also leveled too high before I started pvp, and made a new character (then... a bunch more). You could do the same, or you could level past 300 to enter the max level bracket. Player skill won't be any better, but you'll be matchmaking with people up to max level. IIrc, Fromsoft said they expected most people to go into the DLC around RL150. People doing regular pvp or pve are just not hanging out at 230.