my hammer technique

You look balanced, but try going longer with your arms and countersinking more away from the hammer, especially to the right and left with your hips.  Francis Brebner did an exercise with me where he held both my hands together and pulled them around in the front, simulating the hammer swing.  He pulled hard so I had to really countersink  or be pulled over.  You might get somebody to do that with you.  Also read the comments some athletes gave to Tommi and dlbuffy on WFD and Hammer Problems and Hammer Practice Feedback.   Those comments have been helpful to me too.  Hopefully more experienced throwers will watch your videos and give more detailed feedback.  Have fun and go long.