4T65-E transmission help

[AvtoAnton]

Hey guys thank you to anyone who clicked on this and has a possible recommendation 🙂. I bought a 2000 buick lesabre at 147.5k miles (it was well maintained) and now its at 154.5k. At around 153k ive changed the tranny fluid and filter but stupidly listened to the auto parts manager and used low viscosity fluid. Now the issue, anytime i drive now, for the past couple hundred miles after reaching its running temperature and everything is fired up, when the tranny switches gears, instead of doing it smoothly it quickly kicks. Almost like how a jab to the jaw feels. It doesnt hesitate or anything but it just kicks into gear in a way that anyone in the car can feel it (any gear and any speed). I read somewhere something about a pressure solenoid, but not knowledgeable enough. Yesterday i figured it would be good to just replace some of the low viscosity fluid with regular so i swapped out 3 quarts and the fluid that came out had what i believe are metal grains or shavings. Still kicks. Now im very nervous.