2003 Infiniti G35 direct clucth solenoid valve

Transmission problem
2003 Infiniti G35 6 cyl Automatic 52,000 miles

I have a 2003 infiniti g35 coupe with 52,000 miles on it. Last week I pulled out of a parking spot and while I was waiting to take the main road I felt like something came off but it didn't make a noise. I tried to drive on as normal and the car didn't move. Then I pressed the accelarator pedal harder than usual and the car moved very slowly and made a noise like if I was accelarating it very hard. The service engine soon light came on. Since it was late at night I kept going and the car seemed to be working until I stopped again at a traffick light. The car would not move and I had to press the accelarator harder for it to move while it made the noise I previously described. I did a scan on it and I got the P1764 code. It said something about the direct clutch solenoid valve malfunction. What does this mean? Is this a serious damage?Does this mean that my transmission was damaged and that it needs to be overhauled and rebuilt? Is this repair expensive?