sounds like an alignment issue. Get an alignment done. Oh but first check your steering column knuckle and make sure it's still snug. Maybe when you hit a bump hard it jarred it loose? From my experience the rack doesn't just take a shit for no reason. It usually takes time and alot of tell-tell signs( leaking, whining, squealing, wheel shudder, etc.).
Give that a try, but always a good rule, work on steering or suspension = new computer alignment.
good luck.