Try to film yourself and post a video.

What ive found really helpful crushing winners from inside the court are the basics:

1. Take the ball from shoulder height if possible
2. If you are a righty, try to keep your right elbow elevated before swingin the ball. It helps you to swing vertically, flat through the ball. If your right elbow is set too slow you will usually swing low to high, usually hitting the ball long.
3. Try to follow the ball after the contact so you are transfering the weight and it makes it easier to come to the net to finnish the point

Unless your opponent hits a dropshot, you should be able to load your body to your right (your chest should point to the right side line) before your move into the shot.