In need of some help.

Hey everyone!
Wow, I havent posted on here in a while. Well, I was hoping for some critque/help. I think my main problem is that I sit down too early (which is greatly seen in the first jump). I'm just not sure how to correct this problem.

We did a lot of jumping today, but I only had time to throw this short video together. It was my first time doing 2'6 with him since November because we have been working super hard on our flatwork. So we are rusty and I'm trying to get our distances better, but he didn't rush at all today. Which has been our HUGE problem since I've gotten him. So needless to say I'm quite thrilled with him right now. But enough rambling, help me please!

*also I will be using my actual jumping saddle soon, my leathers are to short so I'm currently getting new ones*

Thanks!