I totally understand where you are coming from. I have a 10 year old thoroughbred and when I first got him he was super forward. I really agree with Joe-Joe’s idea of riding him bareback. This usually helps me. If I am in the saddle and my horse is being energetic, I will also just drop my stirrups for a bit. It helps me a lot, but some people think differently. I would also suggest loads of figures in your warm ups. This always helps my horse focus and relax. Another suggestion is to allow him to have a long and low neck in between your dressage exercises. I usually find that my horse is so much more willing to stretch down after we have done some dressage. Hope this helps. Have a great ride!