Wet weather racing with controller

The car is uncontrollable on wet weather conditions. I go from being competitive at the top when dry to being 2 seconds off the pace of 20th when wet. Going from dry tyres to wet tyres and you notice no grip difference at all. In Mexico for example in the quick corners section in S2, you cant make it through without flying off into a wall. I've tried different setups and its still the same. I think it could be something to do with the level of grip with the tyres.