Starting and Sputtering Problems
 

Hey guys, long time viewer but first time poster on the site. I've looked through a bunch of old threads and tried to see what would help me most but I decided it might be best to just bite the bullet and see if anyone can help me with this since I admittedly don't have great knowledge when it comes to mechanics. I have an '05 G35x Auto Transmission and literally just passed 100k miles and have had no problems. (Bought the car used 3 years ago at 70k). Yesterday, however, when starting the car the engine turned over and grinded but didn't catch for about 5 seconds and its continued like that til now. Also when driving it feels like the car wants to stay in second gear and will rev to high rpm's before shifting and when it does shift it lurches and causes the car to buck. It just never feels natural and when stopped at a red light or stop sign I feel as if the car is about to stall. I'm thinking it maybe it has something to do with the transmission but I'm not sure. If anyone has any advice or could help I'll be forever grateful