Hi. I’m new here and have a problem I’m hoping someone can help with. I have an 07’ Chevy 3500hd ext wheelbase non dually and out of the blue I went to start the truck and it shifts extremely hard into gear but will only move in Reverse. When in drive it slams into gear and then when you let off the brake the truck is still sitting still, if you give it a lot of gas, the truck will move forward but not driveable. I only did that once and haven’t messed with it since. Feels almost like the brakes are on and holding the truck back but they aren’t engaged, e brake is not down. Reverse works fine. Any thoughts?