I don't overclock any more, so I'm a bit out of touch, but adding 0.30V on the CPU seems like a lot to me. Think I would try and reseat the CPU as high heat (could) have caused a poor contact. I hope that's all it might be, but otherwise I suspect that your CPU might not be very well at all 😞
Other folks here might be able to tell you if the CPU might have been damaged or how likely it is. I think about 1.35V would often be considered a 'safe' maximum. What voltage did you take it up to? I'm assuming you have a 2600X right?