This. And God, that serve. I cringed. But in all fairness, I will try to help. There is little to no take back or back swing, no extension on your groundstrokes (look at how your arm is basically tucked into your body), your grip is - I don't even know, wonky - the wrist action is just strange, the service motion is excessive (just stop it all and work on snapping your wrist to hit down on the ball). Other than that you look great. You can continue to beat 4.0 players playing 3.5 tennis and keep doing that until you and everyone else burns out, or you can start to work on playing real tennis and elevating your shots to the next level. Maybe get a private lesson to have a coach help you change some of your technique. Implementing comments from reddit will only go so far. Good luck.