I am stuck!

I am stuck in this pose Eka Pada Sirsasana. Ok, not like I can not get myself out from the pose but I can not make it to the next. Coz of boxing my shoulders are turned forward and I compress my chest and collar bone to much. I should lift my chest up with my strong shoulders but I can not, coz I have monkey shoulders. It sucks coz I know I can do the pose with my legs but I am just not strong enough to press my chest back. I know pations, aweeee! My mind wants to move forward but my body tells me no. Just like when I puched myslef in muaythai so much that I dislocated my shoulder. I should learn by now to be more patience. When I teach people I always talk about pations and how long time it takes to get somewhere, aspecially in muaythai. It takes so much focus by firt understanding then feeling then to get it as a habbit. I am now there and I just dont have the pations at all, hehe! Its easy to tell someone and a complete diffrent thing to do on my own.