When I shift from park to reverse it jumps hard and when I have it in drive the neutral light flashes and it jumps into neutral
My car has an automatic transmission.
The most straightforward possibility here is that the transmission range sensor and the shift linkage itself are misaligned. The range sensor provides an electronic "here’s the gear I am in" to the transmission controller, and other interested electronic components. The misalignment is causing the electronic portions of the transmission to switch gears from what is mechanically selected. If you need to have this checked, a certified professional from YourMechanic, can come to your car’s location to diagnose the shifting problem and pinpoint the appropriate repair.