Some help for the handle

Okay, doing some Backroll's on the tramp since last winter and being practice the backroll behind the boat since the beginning of the saison. I can get the backroll perfect, land 8 out of the 10 times on the board, just after the second wake. Nice/perfect rotation, and height (according other boarders). But.... I never hold that damn handle. All of I think about when starting the backroll is; "hold the handle" and at 3/4-7/8 of the roll I let it go. Any suggestions? It already cost me alot of beers and frustration and I need to land this trick this saison or I would really start doubting myself (besides I lose a bbq for alot of people)... So any small suggestions would be helpfull (and no glue or tape sollutions please ).