Center Console Boats And More

Trouble Getting Up with a Wakeboard?

I recently started wakeboarding behind a pontoon w/ a 150 engine behind it (it will pull me out easily on skis). The rope is attached to a ski bar. When I give the signal to go, I can only hold on for about 2 seconds. I am literally holding on with everything that I have. Is there something that I'm doing wrong? Also, would it make it easier if the boat had a waketower? A friend of mine who started the same time I did already got up behind his speedboat w/ a wake tower.
Also a few friends of mine tried it behind the pontoon, so I don't think it is something with me.
Basically, there is so much tension in the line it just pulls my arms over my board and I can't hold on any longer.