Try it from a "spider position" as we call it. Sit on the ground, then put your legs over your slightly bent elbows and kind of let them rest there. Then press the bottom of the ground, straighten legs and arms and press from there. I can PM a video if needed.
This method helps to get the very first press up. When mastered, it's easier to transfer to real, clean press form seating. But getting to the handstand this way has helped many of my athletes to believe in themselves and actually get a feeling of a real press.