Maybe try an open stance too. Or really sideways, but not always your front leg crossing.
Keep the after swing more limited? So it's a more symmetrical swing. Little backswing preparation then hit it and don't swing your racket in front of your body too much. Unless you're hitting with a lot of power.
Try using more body momentum, turn your shoulders. As an experiment, try to hit without moving your arms too much. Just turn your shoulders and your hips.
Honestly, it doesn't look too bad at all. Just keep practicing, and you will be able to relax your body more.