Rex RS 450 suddenly throttled while driving

Hey guys, I have a problem and I can’t help at the moment. At my Rex earlier on, I think the electronic throttle is activated. Now it doesn’t turn up fully and still runs 35km/h. The whole thing is a shaky thing, as from he wants faster, but can’t. The blue cable on the CDI is severed and the ends had no contact. I hope someone can help me further.