Luckily this happened near home. I have a 2004 G35x

I was driving then all of the sudden it felt like I lost power. I switched to manumatic and saw that I was in second. Tried up shifting dashboard indicator reads 3 but I'm just limping along. Turned the car around and limped home. The engine runs fine but when I shift into D or R it's like I'm in N. Manumatic is out too. Any ideas?

 

You might have burnt the clutch disks in your trans. Go put it in each gear in manual mode and if you punch it and it slips then your trans needs a rebuild. good luck