98 ES300 Cruise Control Help
 

I've got a 98 ES300 and I think the cruise control is going bad. When I'm driving above 60 mph the car starts to slow me down even if I don't have the cruise control on. But if I let off the gas and then get back on it, the car starts picking up speed again. I drove from FL to NC this past week and when in cruise, it ran perfectly and I only have this problem when I'm out of cruise control.
So my question is where is the relay on the cruise control so I can change it out, or is there even a relay for the cruise control? Hope this fixes the problem or if someone has an other suggestions, please let me know. THANKS!